ACTIVITY BOOK2nd Edition2APart 1 Explore the world of Shaping Maths with Aini, Bala, Caili and David on their journey to the six fantastic Mathematics islands. At each level, Shaping Maths offers a wide range of learning experiences, taking pupils from the concrete through the pictorial to the abstract mode of mathematical representation. Through clear presentation and a highly structured and spiral approach, the package provides pupils with a strong mathematical foundation and develops higher order thinking skills. Using a thematic approach, pupils are able to connect their everyday life experiences with Mathematics, thus encouraging active pupil participation and learning. Shaping Maths is an up-to-date instructional package designed to meet the learning needs of pupils from Primary 1 to 6. The Primary 2 package consists of two coursebooks, four activity books, and a teacher’s resource pack. Shaping Maths makes Mathematics engaging, accessible and fun! Bala Caili Aini David Shaping Maths Activity Book 2nd Edition 2A Par t 1 S h a p i n g M a t h s C h a r l o t t e C o l l a r s • K o a y P h o n g L e e • L e e N g a n H o e • T a n C h e o w S e n g P a r t 1 A C T I V I T Y B O O K 2 n d E d i t i o n 2 A Charlotte Collars • Koay Phong Lee • Lee Ngan Hoe • Tan Cheow Seng SMAB2A_Cover_pt1. 1 1/15/08 10:06:54 AM Charlotte Collars • Koay Phong Lee • Lee Ngan Hoe • Tan Cheow Seng (Cert. Ed.) (Ph.D.) (M.Sc.Ed.) (Cert. Ed.) ACTIVITY BOOK 2nd Edition 2A Part 1 • A P P R O V E D B Y M INISTRY O F E D U C A T I O N • f o r u s e from 20 0 7 - 2 0 1 1 © 2007 Marshall Cavendish International (Singapore) Private Limited Published by Marshall Cavendish Education An imprint of Marshall Cavendish International (Singapore) Private Limited A member of Times Publishing Limited Times Centre, 1 New Industrial Road, Singapore 536196 Customer Service Hotline: (65) 6411 0820 E-mail:
[email protected] Website: www.marshallcavendish.com/education/sg First published 2007 Second impression 2008 Reprinted 2009 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner. ISBN 978-981-01-6528-4 Edited by: Goh Jia Zhan and Yee Pey Ling Designed by: Henny Irawati Cover design by: Winnie Ng Printed in Singapore by C.O.S. Printers Pte Ltd ©981-01-6528-4.indd 1 1/11/08 5:29:56 PM Hoppy 8oking Ì need 125 g of butter. Ì need 50 g more f our thon sugor. The totol moss of the sugor ond butter is 460 g. Whot is the recipe? Fill in the missing numbers below. Roisin Coke g butter g sugor g f our g roisins Coili wonts to boke o roisin coke. She tries to recoll the recipe. 2 eggs 1 teospoon vonillo essence Holf cup of milk Ì need 30 g less roisins thon f our. Let’s Find Out 12 4 Moss: Let's F|nd Dut 26 Fill in the blonks with cm or m. o) Doddg's height is obout 174 . b) The length of our school feld is obout 120 . c) The length of o pencil is obout 18 . d) The width of the holl is obout 20 . 27 PREFACE Shaping Maths is an instructional package written according to the latest Primary Mathematics Syllabus provided by the Ministry of Education, Singapore. The package is designed to meet the learning needs of pupils from Primary 1 to 6. For Primary 2, the package consists of two coursebooks, four activity books and a teacher’s resource pack. Continuing research in education has resulted in the introduction of new features in the second edition. Through these features, educators are further equipped with various strategies in addressing teaching and learning needs. These features also include more open-ended questions to encourage exploration and in-depth thinking among pupils. Thus, mathematically inquisitive learners are born! Features Question Classification – pre-requisite skills – reinforcement of current concepts – higher-order thinking skills Helps teachers to spend their time more effectively by using the appropriate questions to get pupils to master the necessary skills. Let’s Find Out Engages pupils in mathematical self-discovery or investigation that promotes mathematical thinking. My Maths Journal Contains reflection worksheets to develop pupils into self-regulated learners. 64 Soft drinks 0 2 1 3 kg 4 5 6 7 8 9 3 kg 2 kg o) Fill in the blonks. 1 b) Fill in the blonks with more or Iess. The moss of the corton of soft drinks is kg. The moss of the tin of milk powder is kg. The moss of the sock of rice is thon 4 kg. The moss of the bottle of oil is thon 3 kg. 4 kg Review 2 Review Exercises Helps pupils to consolidate their learning. 80 My Moths Jcurno| W rite or drow whot gou know obout m ultiplicotion. W rite o m ultiplicotion storg for this picture. 2 A U nìt 5 M u|tìp|ìcctìen cnd Dìvìsìen 82 My Maths Journal M y Favourite M athem atics A ctivity This Term W rite about the activity. Draw to show the activity. O E N T C N T S 1 Numbers to 1000 Looking Back − Tens and Ones Activity 1 1 Looking Back − Counting by Tens and Ones Activity 2 3 Counting Beyond 100 Activity 3 5 Hundreds, Tens and Ones Activity 4 9 Comparing and Ordering Numbers Activity 5 13 Activity 6 15 Let’s Find Out 17 2 Addition and Subtraction Within 1000 Meanings of Addition and Subtraction Activity 1 18 Addition Without Renaming Activity 2 21 Activity 3 23 Subtraction Without Renaming Activity 4 24 Activity 5 26 Addition With Renaming (1) Activity 6 27 Activity 7 29 Addition With Renaming (2) Activity 8 30 Activity 9 32 Subtraction With Renaming (1) Activity 10 34 Activity 11 36 Subtraction With Renaming (2) Activity 12 37 Activity 13 39 Solving Two-step Word Problems Activity 14 40 Let’s Find Out 42 3 Length Measuring Length in Metres Activity 1 43 Measuring Length in Centimetres Activity 2 45 Activity 3 47 Solving Word Problems Activity 4 50 Let’s Find Out 53 Review 1 54 My Maths Journal 67 SMAB2A_Content_pt1 1 3/30/07 11:11:16 AM Colour the correct number of squares. Then fill in the missing numbers. a) b) 43 is 40 and . 33 is and 3. 1 Activity 1 Unit 1 1 1 Numbers to 1000: Looking Back – Tens and Ones Count the tens and ones. Then fill in the missing numbers. a) b) tens ones = tens ones = 2 2 8 28 6 0 60 3 30 2 1 Numbers to 1000: Looking Back – Tens and Ones Write the numbers in words. Look at the example below. a) b) 7 7 0 5 0 2 fifty-two c) d) Write in numbers. Look at the example below. a) b) 65 9 o n e s 8 te n s 5 o n e s 6 te n s 0 o n e s 9 te n s 1 0 te n s 0 o n e s 3 4 c) d) 80 6 0 4 0 89 100 90 seventy-seven eight-six forty SMAB2A_01_pt1. 2 10/23/06 11:07:59 AM 3 1 Numbers to 1000: Looking Back – Counting by Tens and Ones Complete the number line. a) 10 more than 47 is . 47 + 10 = b) 10 less than 47 is . 47 – 10 = 7 17 27 67 a) 1 more than 35 is . 35 + 1 = b) 1 less than 35 is . 35 – 1 = 1 2 Activity 2 Unit 1 Complete these sentences. 36 36 34 34 37 47 57 57 57 37 37 SMAB2A_01_pt1. 3 10/23/06 11:08:09 AM 4 1 Numbers to 1000: Looking Back – Counting by Tens and Ones Fill in the missing numbers. Look at the examples below. a) b) Circle the correct answers. Look at the example below. 3 4 1 more 10 less 10 more 1 less 54 55 1 more 10 less 10 more 1 less 80 90 a) b) c) d) – 1 100 99 – 10 + 1 63 73 + 10 – 1 40 30 – 10 + 1 27 28 + 10 56 45 65 81 70 79 SMAB2A_01_pt1. 4 10/23/06 11:08:11 AM 5 1 Numbers to 1000: Counting Beyond 100 Count and write the number in the box. Then write the number in words. a) b) c) 1 Activity 3 Unit 1 603 six hundred and three 460 four hundred and sixty 245 two hundred and forty-five 6 1 Numbers to 1000: Counting Beyond 100 422 700 819 a b 2 a) 100 more than 354 is . b) 100 less than 354 is . 3 a) What number is 100 less than the given number? b) What number is 100 more than the given number? 100 less 100 more 454 254 322 522 600 800 719 919 SMAB2A_01_pt1. 6 10/23/06 11:08:15 AM 7 1 Numbers to 1000: Counting Beyond 100 a) Start at 216. Count on in tens. Colour the trail of tens in red. b) Start at 855. Count backwards in hundreds. Colour the trail of hundreds in blue. 845 835 795 805 855 755 825 815 155 320 655 400 255 220 516 555 455 355 219 416 236 246 256 218 316 226 136 266 217 216 116 156 276 196 176 286 B A c) Which mouse gets the cheese? Mouse Which mouse reaches the mouse trap? Mouse 4 B A SMAB2A_01_pt1. 7 10/23/06 11:08:17 AM 8 1 Numbers to 1000: Counting Beyond 100 Study the number line below. a) What number is 1 more than 203? b) What number is 10 less than 203? 5 190 200 203 6 868 268 768 568 Study each number pattern and fill in the next two numbers. a) 88 188 288 b) 476 486 496 c) 760 750 740 d) 232 231 230 7 a) Complete the number line below. b) What number is 100 more than 568? c) What number is 100 less than 568? 204 193 368 468 668 668 468 388 488 506 516 730 720 229 228 SMAB2A_01_pt1. 8 10/23/06 11:08:19 AM 9 1 Numbers to 1000: Hundreds, Tens and Count the hundreds, tens and ones. Then fill in the missing numbers. a) hundreds tens ones = b) hundreds tens ones = c) hundreds tens ones = 1 Activity 4 Unit 1 3 2 3 323 6 4 0 640 7 0 7 707 SMAB2A_01_pt1. 9 10/23/06 11:08:23 AM 10 1 Numbers to 1000: Hundreds, Tens and Match. 916 • • Six hundred and nineteen 169 • • Six hundred and ninety 619 • • One hundred and sixty-nine 690 • • Nine hundred and sixty-one 961 • 2 SMAB2A_01_pt1. 10 10/23/06 11:08:26 AM 11 1 Numbers to 1000: Hundreds, Tens and 3 Write the numbers in words. 411 505 838 4 Fill in the blanks. a) In 358, the digit is in the ones place. b) In 672, the digit is in the hundreds place. c) In 834, the digit is in the tens place. d) In 980, the digit is in the ones place. four hundred and eleven five hundred and five eight hundred and thirty-eight 8 6 3 0 SMAB2A_01_pt1. 11 10/23/06 11:08:30 AM 12 1 Numbers to 1000: Hundreds, Tens and 5 Fill in the missing numbers. a) b) 213 327 200 + 10 + 300 + + 7 c) d) 449 580 + 40 + 9 500 + e) f) hundreds tens ones 600 + 30 + 8 700 + 40 + 6 g) h) hundreds hundreds tens tens ones ones 800 + 50 900 + 2 3 20 400 80 638 7 4 6 8 5 0 9 0 2 SMAB2A_01_pt1. 12 10/23/06 11:08:33 AM 13 1 Numbers to 1000: Comparing and Ordering Numbers 1 a) What number does each picture show? b) Which number is smaller? 2 a) What number does each picture show? b) Which number is greater? Activity 5 Unit 1 353 333 353 240 153 153 SMAB2A_01_pt1. 13 10/23/06 11:08:38 AM 14 1 Numbers to 1000: Comparing and Ordering Numbers 3 a) Write the correct answers in the boxes. 4 597 = hundreds tens ones 419 = hundreds tens ones 508 = hundreds tens ones b) Which number is the smallest? c) Which number is the greatest? Arrange these numbers in order. Begin with the greatest number. 437 409 432 5 Arrange these numbers in order. Begin with the smallest number. 308 298 306 275 greatest smallest 5 9 7 4 1 9 5 0 8 419 597 437 432 409 275 298 306 308 SMAB2A_01_pt1. 14 10/23/06 11:08:40 AM 15 1 Numbers to 1000: Comparing and Ordering Numbers Hundreds Tens Ones An example ➞ 1 6 8 You are given three cards: a) Use these cards to form numbers between 100 and 1000. List all the possible numbers in the table below. 1 6 8 1 b) i) Which two numbers have the greatest hundreds? ii) Between these two numbers, which is greater? c) i) Which two numbers have the smallest hundreds? ii) Between these two numbers, which is smaller? d) Arrange the numbers listed in a) in order. Begin with the smallest number. Activity 6 Unit 1 1 8 6 6 1 8 6 8 1 8 1 6 8 6 1 816, 861 861 168, 186 168 168, 186, 618, 681, 816, 861 SMAB2A_01_pt1. 15 10/23/06 11:08:42 AM 16 1 Numbers to 1000: Comparing and Ordering Numbers You are given three cards. a) Write any number from 1 to 9 on the second and third cards. b) Use these three cards to form numbers between 100 and 1000. i) What is the greatest 3-digit number formed? ii) What is the smallest 3-digit number formed? 0 2 You are given four cards. Use three of these cards to form numbers between 100 and 1000. a) What is the greatest 3-digit number formed? b) What is the smallest 3-digit number formed? 3 8 6 9 9 Answer varies 998 689 Answer varies Answer varies SMAB2A_01_pt1. 16 10/23/06 11:08:43 AM 17 1 Numbers to 1000: Let’s Find Out Let’s Find Out Number Riddle 2 I shall find the answer by working backwards. What is the tens digit? What is the hundreds digit? I am thinking of a 3-digit number. I can get the hundreds digit by adding the tens digit and the ones digit. The tens digit is 2 more than the ones digit. The ones digit is 2. What is the number that I am thinking of? 6 4 SMAB2A_01_pt1. 17 10/23/06 11:08:45 AM 18 2 Addition and Subtraction Within 1000: Meanings of Addition and Subtraction part whole part 29 20 9 part whole part 57 50 7 Fill in the missing number. a) 20 + 9 = 9 + 20 = 29 – 9 = 29 – 20 = 9 more than 20 is . is 9 less than 29. b) 50 + 7 = 7 + 50 = 57 – 50 = 57 – 7 = 7 more than 50 is . is 7 less than 57. 1 Activity 1 Unit 2 29 29 20 9 29 20 57 57 7 50 50 57 SMAB2A_02_pt1..indd 18 10/23/06 11:59:45 AM 19 2 Addition and Subtraction Within 1000: Meanings of Addition and Subtraction part whole part 50 40 10 c) 40 + 10 = 10 + 40 = 50 – 40 = 50 – 10 = 10 more than 40 is . is 10 less than 50. 2 Put ✓ next to the number sentence which matches the story. a) Mrs Muthu made 20 apple pies and 15 meat pies. How many pies did she make altogether? 20 + 15 = 35 20 – 15 = 5 Mrs Muthu made pies altogether. Activity 1 50 50 10 40 50 40 35 SMAB2A_02_pt1..indd 19 10/23/06 11:59:46 AM 20 2 Addition and Subtraction Within 1000: Meanings of Addition and Subtraction d) Aimin paid $25 for a dress. She had $24 left. How much money had she at first? $25 + $24 = $49 $25 – $24 = $1 She had $ at first. b) Ali has 46 bookmarks. He gives 12 bookmarks to his friend. How many bookmarks has he left? 46 + 12 = 58 46 – 12 = 34 Ali has bookmarks left. c) Lin used 57 blue ribbons and 25 red ribbons. How many more blue ribbons than red ribbons did she use? 57 + 25 = 82 57 – 25 = 32 Lin used more blue ribbons than red ribbons. 34 32 49 SMAB2A_02_pt1..indd 20 10/23/06 11:59:47 AM 21 2 Addition and Subtraction Within 1000: Addition Without Renaming 43 + 156 = 106 + 82 = 4 3 + 1 5 6 1 0 6 + 8 2 30 + 431 = 215 + 763 = + + 1 2 63 + 120 = 6 3 + 1 2 0 Activity 2 Unit 2 183 1 8 3 1 9 9 1 8 8 4 6 1 9 7 8 4 3 1 7 6 3 3 0 2 1 5 199 188 461 978 SMAB2A_02_pt1..indd 21 10/23/06 11:59:50 AM 22 2 Addition and Subtraction Within 1000: Addition Without Renaming Mars Jupiter Neptune Saturn 3 a) Work out all the answers. Then colour the boxes where the answer is 568. b) Bala travelled along the path formed by the coloured boxes. Which planet did he land on? 5 5 2 + 1 6 5 6 8 1 6 3 + 4 2 4 2 5 7 + 2 4 2 5 0 5 + 6 3 2 2 3 + 3 4 5 3 3 1 + 2 3 7 3 8 + 5 4 0 3 6 4 + 1 0 4 4 4 1 + 1 2 8 5 6 8 5 7 8 5 6 8 4 6 8 5 8 7 5 6 8 5 6 9 4 9 9 Neptune SMAB2A_02_pt1..indd 22 10/23/06 11:59:52 AM 23 2 Addition and Subtraction Within 1000: Addition Without Renaming 1 3 2 Mrs Chen sold 150 buns in the afternoon. She sold 127 buns in the evening. How many buns did she sell altogether? 150 + 127 = She sold buns altogether. Devi has 214 beads. Her sister has 45 more beads than her. How many beads does Devi’s sister have? Devi’s sister has beads. Mr Lim spent $343. He had $125 left. How much money did he have at first? He had $ at first. 1 5 0 + 1 2 7 Activity 3 Unit 2 277 277 2 7 7 259 468 SMAB2A_02_pt1..indd 23 10/23/06 11:59:54 AM 24 2 Addition and Subtraction Within 1000: Subtraction Without Renaming 1 358 – 125 = 3 5 8 – 1 2 5 2 189 – 36 = 358 – 240 = 1 8 9 – 3 6 3 5 8 – 2 4 0 879 – 259 = 909 – 403 = – – Activity 4 Unit 2 233 2 3 3 153 118 1 5 3 1 1 8 6 2 0 5 0 6 2 5 9 4 0 3 8 7 9 9 0 9 620 506 25 2 Addition and Subtraction Within 1000: Subtraction Without Renaming Greenland China Mali Malaysia 3 a) Work out all the answers. Then colour the boxes where the answer is 34. b) Bala travelled along the path formed by the coloured boxes. Where did he land? 1 9 4 – 1 6 0 3 4 1 6 8 – 1 3 3 2 4 4 – 1 1 0 1 7 6 – 1 4 2 6 8 9 – 6 5 5 3 3 9 – 3 0 5 2 5 8 – 3 4 8 8 9 – 7 6 4 4 3 5 – 4 0 1 3 4 2 2 4 3 4 1 2 5 3 5 3 4 3 4 1 3 4 Malaysia 26 2 Addition and Subtraction Within 1000: Subtraction Without Renaming There were 476 people at a concert. 250 of them were adults. How many children were there? 476 – 250 = There were children. David has 168 toy soldiers. Tom has 58 fewer toy soldiers than David. How many toy soldiers does Tom have? Tom has toy soldiers. Sally went shopping with $478. She bought a handbag and had $264 left. How much did she pay for the handbag? She paid $ for the handbag. 1 4 7 6 – 2 5 0 2 3 Activity 5 Unit 2 226 226 2 2 6 110 214 SMAB2A_02_pt1..indd 26 10/23/06 12:00:02 PM 27 2 Addition and Subtraction Within 1000: Addition With Renaming (1) 67 + 125 = 159 + 70 = 138 + 245 = 654 + 155 = 1 266 + 153 = 2 6 6 + 1 5 3 6 7 + 1 2 5 2 + 1 5 9 + 7 0 + Activity 6 Unit 2 419 4 1 9 1 9 2 2 2 9 8 0 9 192 229 383 809 3 8 3 2 4 5 1 3 8 1 5 5 6 5 4 SMAB2A_02_pt1..indd 27 10/23/06 12:00:08 PM 28 2 Addition and Subtraction Within 1000: Addition With Renaming (1) Mark these addition sums. Put ✓ in the box if the answer is correct. Put ✗ in the box if the answer is wrong. Then show the correct way of adding. Sum How you Correct answer should add a) 178 + 14 = b) 252 + 18 = c) 658 + 129 = d) 537 + 56 = e) 648 + 190 = 3 1 7 8 + 1 4 1 8 2 1 7 8 + 1 4 2 5 2 + 1 8 2 7 0 2 5 2 + 1 8 6 5 8 + 1 2 9 7 7 7 6 5 8 + 1 2 9 5 3 7 + 5 6 6 9 3 5 3 7 + 5 6 6 4 8 + 1 9 0 8 4 8 6 4 8 + 1 9 0 1 9 2 7 8 7 5 9 3 8 3 8 192 787 593 838 SMAB2A_02_pt1..indd 28 10/23/06 12:00:09 PM 29 2 Addition and Subtraction Within 1000: Addition With Renaming (1) Mr Wu delivered 158 letters in the morning. He delivered 90 letters in the afternoon. How many letters did he deliver altogether? 158 + 90 = He delivered letters altogether. Osman has 452 postcards. Aminah has 97 more postcards than Osman. How many postcards does Aminah have? Aminah has postcards. 247 women and 148 men work in a factory. How many workers are there in the factory? There are workers in the factory. 1 5 8 + 9 0 3 2 1 Activity 7 Unit 2 248 248 2 4 8 549 395 SMAB2A_02_pt1..indd 29 10/23/06 12:00:11 PM 30 2 Addition and Subtraction Within 1000: Addition With Renaming (2) 87 + 635 = 246 + 575 = 8 7 + 6 3 5 2 4 6 + 5 7 5 528 + 96 = 398 + 409 = + + 1 177 + 254 = 1 7 7 + 2 5 4 2 Activity 8 Unit 2 431 4 3 1 722 821 7 2 2 8 2 1 6 2 4 8 0 7 9 6 4 0 9 5 2 8 3 8 9 624 807 SMAB2A_02_pt1..indd 30 10/23/06 12:00:15 PM 31 2 Addition and Subtraction Within 1000: Addition With Renaming (2) a) Add. 3 0 4 + 3 9 6 5 3 6 + 2 8 7 6 5 9 + 2 5 4 4 3 5 + 3 6 7 5 6 4 + 2 6 9 3 8 4 + 3 6 6 700 keep 650 tidy 833 and 903 room 750 clean 733 or 802 green 823 our 913 country 805 neat 3 b) Help Mr Froggie cross the pond by colouring the leaves that match the answers above. c) Write down the message given on the coloured leaves. 7 0 0 8 0 2 8 2 3 8 3 3 9 1 3 7 5 0 Keep our country clean and green. or Keep our country green and clean. SMAB2A_02_pt1..indd 31 10/23/06 12:00:20 PM 32 2 Addition and Subtraction Within 1000: Addition With Renaming (2) 1 2 3 Mr Hamid bought a watch and a pair of shoes. How much did he spend altogether? $368 + $158 = He spent $ altogether. An oven costs $197 more than a toaster. What is the cost of the oven? The cost of the oven is $ . Leo saved $346. Jenny saved $185 more than Leo. How much money did Jenny save? Jenny saved $ . 3 6 8 + 1 5 8 Activity 9 Unit 2 526 526 5 2 6 305 531 SMAB2A_02_pt1..indd 32 10/23/06 12:00:22 PM 33 2 Addition and Subtraction Within 1000: Addition With Renaming (2) Bala had some stamps. He gave 159 stamps to David. He has 279 stamps left. How many stamps did Bala have at first? Bala had stamps at first. Mrs Wang needs 350 blue beads, 265 red beads and 125 yellow beads to make a bag. How many beads does she need altogether? She needs beads altogether. Mr Soon had $112 left after buying a leather bag and a wallet. How much money did he have at first? He had $ at first. $325 $85 4 3 5 0 2 6 5 + 1 2 5 6 5 438 7 4 0 740 522 SMAB2A_02_pt1..indd 33 10/23/06 12:00:24 PM 34 2 Addition and Subtraction Within 1000: Subtraction With Renaming (1) 294 − 118 = 518 − 126 = 754 − 136 = 570 − 316 = 1 416 – 233 = 4 1 6 – 2 3 3 2 Subtract. 2 9 4 – 1 1 8 5 1 8 – 1 2 6 Activity 10 Unit 2 – – 183 1 8 3 176 392 1 7 6 6 1 8 2 5 4 1 3 6 3 1 6 7 5 4 5 7 0 618 254 3 9 2 SMAB2A_02_pt1..indd 34 10/23/06 12:00:27 PM 35 2 Addition and Subtraction Within 1000: Subtraction With Renaming (1) 6 4 5 – 1 9 0 7 8 1 – 5 2 8 8 5 8 – 6 6 6 6 7 9 – 2 8 1 9 1 6 – 4 2 5 8 6 7 – 3 7 6 5 6 2 – 1 2 3 8 4 0 – 4 1 8 B O U Z L A E R D 4 2 2 1 9 2 4 3 9 1 5 1 4 9 1 1 3 7 2 5 3 4 5 5 3 9 8 8 3 2 – 6 8 1 3 U s e t h e c o d e s a t t h e b o t t o m o f t h e p a g e t o s o l v e t h i s r i d d l e : “ W h a t d o y o u c a l l a s l e e p i n g b u l l ? ” 7 1 3 8 6 – 2 4 9 1 3 7 A B U L L D O 1 5 1 Z E R 4 2 2 4 3 9 4 9 1 4 9 1 3 9 8 1 9 2 2 5 3 4 5 5 SMAB2A_02_pt1..indd 35 10/23/06 12:00:28 PM 36 2 Addition and Subtraction Within 1000: Subtraction With Renaming (1) There are 193 mangoes in a basket. 25 of them are green. How many mangoes are not green? 193 – 25 = mangoes are not green. Roy collected 250 phonecards. Helen collected 38 fewer phonecards than Roy. How many phonecards did Helen collect? Helen collected phonecards. Meimei went shopping with $215. She spent $194. How much money did she have left? She had $ left. 1 9 3 – 2 5 1 2 3 Activity 11 Unit 2 168 168 1 6 8 212 21 250 – 38 = 212 $215 – $194 = $21 SMAB2A_02_pt1..indd 36 10/23/06 12:00:30 PM 37 2 Addition and Subtraction Within 1000: Subtraction With Renaming (2) 1 215 – 186 = 2 1 5 – 1 8 6 314 − 68 = 460 − 297 = 657 − 268 = 703 − 425 = 2 Subtract. 3 1 4 – 6 8 4 6 0 – 2 9 7 Activity 12 Unit 2 – – 29 2 9 246 163 3 8 9 2 7 8 2 6 8 4 2 5 6 5 7 7 0 3 278 389 2 4 6 1 6 3 SMAB2A_02_pt1..indd 37 10/23/06 12:00:33 PM 38 2 Addition and Subtraction Within 1000: Subtraction With Renaming (2) 7 0 0 – 3 2 5 6 2 1 – 5 2 3 7 2 2 – 2 6 9 L O N P V E 9 8 1 0 9 1 7 8 3 7 5 4 5 3 7 5 6 9 0 0 – 1 4 4 3 5 0 7 – 3 9 8 U s e t h e c o d e s a t t h e b o t t o m o f t h e p a g e t o s o l v e t h i s r i d d l e : “ W h a t i s a n 8 - l e t t e r w o r d t h a t h a s o n l y 1 l e t t e r i n i t ? ” 9 2 5 – 1 6 9 9 4 1 – 1 8 5 8 2 1 – 6 4 3 E N V E L O P E 7 5 6 1 7 8 4 5 3 3 7 5 7 5 6 9 8 1 0 9 7 5 6 SMAB2A_02_pt1..indd 38 10/23/06 12:00:34 PM 39 2 Addition and Subtraction Within 1000: Subtraction With Renaming (2) 1 2 3 On Saturday, 353 people visited a food stall. On Sunday, 421 people visited the same stall. How many more people visited the stall on Sunday than on Saturday? 421 – 353 = more people visited the stall on Sunday than on Saturday. Hassan sold 532 sticks of chicken satay. He sold 155 fewer sticks of mutton satay. How many sticks of mutton satay did he sell? He sold sticks of mutton satay. There were 420 guests at a grand dinner. 245 of the guests wore ties. How many guests did not wear ties? guests did not wear ties. 4 2 1 – 3 5 3 Activity 13 Unit 2 68 377 175 6 8 68 532 – 155 = 377 420 – 245 = 175 SMAB2A_02_pt1..indd 39 10/23/06 12:00:35 PM 40 2 Addition and Subtraction Within 1000: Solving Two-step Problems 1 2 Mr Salleh paid $688 for a watch. He paid $520 less for a tie-pin than the watch. a) How much did he pay for the tie-pin? b) How much did he pay altogether for the watch and the tie-pin? a) He paid $ for the tie-pin. b) He paid $ altogether. Mr Lee used 135 m of cloth to make curtains. He used 67 m more to make cushion covers than the curtains. a) How much cloth did he use to make cushion covers? b) How much cloth did he use altogether to make curtains and cushion covers? a) He used m of cloth to make cushion covers. b) He used m of cloth altogether. Activity 14 Unit 2 168 856 202 337 (a) $688 – $520 = $168 (b) $688 + $168 = $856 (a) 135 + 67 = 202 (b) 135 + 202 = 337 SMAB2A_02_pt1..indd 40 10/23/06 12:00:37 PM 41 2 Addition and Subtraction Within 1000: Solving Two-step Problems 346 men, 264 women and 135 children took part in a fancy dress parade. a) How many adults took part? b) How many fewer children than adults took part? a) adults took part. b) fewer children than adults took part. Tom, Ali and Lam are bakers. Tom used 275 kg of flour this week. Ali used 18 kg less flour than Tom. Lam used 35 kg more flour than Tom. a) How much flour did Ali use? b) How much flour did Lam use? a) Ali used kg of flour. b) Lam used kg of flour. 4 3 610 475 257 310 (a) 346 + 264 = 610 (b) 610 – 135 = 475 (a) 275 – 18 = 257 (b) 275 + 35 = 310 SMAB2A_02_pt1..indd 41 10/23/06 12:00:38 PM 42 2 Addition and Subtraction Within 1000: Let’s Find Out 2 1 Let’s Find Out Faulty Calculator When we add 345 and 123 using a calculator: Press 3 4 5 + 1 2 3 = . What answer does the calculator show? 345 + 123 = Bala has a faulty calculator. The 4 and 7 keys of his calculator cannot work. a) To add 345 and 123, Bala presses 3 3 5 + 1 0 + 1 2 3 = Will he get the correct answer for ‘345 + 123’? Why? b) Which buttons of the calculator should Bala press to find the value of ‘709 – 253’? Show two possible ways by filling in the boxes below. 468 Yes. 335 + 10 + 123 = 468 8 0 9 − 1 0 0 − 2 5 3 = 8 0 9 − 3 5 3 = SMAB2A_02_pt1..indd 42 10/23/06 12:00:40 PM 43 3 Length: Measuring Length in Metres a) Use glue to join two open pages of old newspapers together. Place a metre ruler at the edge like this. b) Draw a strip 1 m long and cut it out using a pair of scissors. c) With your classmates, line the 1-m strips end-to-end along the length of the classroom to measure how long it is. The length of my classroom is about m. d) Now put the strips on the floor along the corridor to find its length. The length of the corridor is about m. 1 m length of classroom 1 metre ruler Activity 1 Unit 3 Answer varies Answer varies SMAB2A_03_pt1.indd 43 10/23/06 12:11:49 PM 44 3 Length: Measuring Length in Metres Guess Check More than Less than More than Less than 1 m 1 m 1 m 1 m Work with a partner. First guess the answers. Then check your answers using a metre ruler or a 1-m string. Put ✓ in the correct boxes. 2 My height My arm’s length My waistline Answers vary Answers vary Answers vary 45 3 Length: Measuring Length in Centimetres Fill in the blanks. a) Ribbon A is cm long. b) Ribbon B is cm long. c) Ribbon C is as long as Ribbon . d) Ribbon D is cm shorter than Ribbon A. e) Ribbon is the shortest. f) Ribbon is the longest. 0 1 2 3 4 5 6 7 8 9 10 cm A B C D 1 Activity 2 Unit 3 7 6 B 2 D A SMAB2A_03_pt1.indd 45 10/23/06 12:11:53 PM 46 3 Length: Measuring Length in Centimetres Stapler: about cm Pencil case: about cm SHAPING MATHS a) Use a ruler to measure the length and breadth of this bookmark. length: cm breadth: cm b) The breadth of the bookmark is cm shorter than the length. Paper clip: about cm Collect these things. Measure their lengths using a ruler. 3 2 10 3 7 Answer varies Answer varies Answer varies SMAB2A_03_pt1.indd 46 10/23/06 12:11:59 PM 47 3 Length: Measuring Length in Centimetres a) Estimate and then measure the length of each line. A B G H C D E F b) Fill in the blanks. Line is as long as Line . Line EF is longer than Line CD by cm. Line Estimate Actual AB CD EF GH 1 Activity 3 Unit 3 Answer varies 5 cm 10 cm 11 cm 10 cm CD GH 1 Answer varies Answer varies Answer varies SMAB2A_03_pt1.indd 47 10/23/06 12:12:01 PM 48 3 Length: Measuring Length in Centimetres How long is each of these lines? Measure them using a string and a ruler. a) Line KL is cm long. b) Line MN is cm long. c) Line is longer than Line . d) Line is shorter than Line . K L N M a) Draw a straight line PQ 7 cm long. b) Draw a straight line RS 2 cm longer than Line PQ. a) Draw a straight line WX 14 cm long. b) Draw a straight line YZ 4 cm shorter than Line WX. 4 3 2 10 9 MN KL KL MN P Q R S W X Y Z SMAB2A_03_pt1.indd 48 10/23/06 12:12:03 PM 49 3 Length: Measuring Length in Centimetres Fill in the blanks with cm or m. a) The height of our school flagpole is about 5 . 5 e) I walk about 50 from my school to the nearest bus-stop every day. d) I am about 10 shorter than my sister. c) The height of my water bottle is about 20 . b) The length of my thumb is about 3 . m cm cm cm m SMAB2A_03_pt1.indd 49 10/23/06 12:12:04 PM 50 3 Length: Solving Word Problems The grey belt is 78 cm long. The black belt is 85 cm long. How much shorter is the grey belt than the black belt? 85 – 78 = The grey belt is cm shorter than the black belt. Aini’s bear is 18 cm tall. Caili’s bear is 15 cm taller than Aini’s. How tall is Caili’s bear? 18 + 15 = Caili’s bear is cm tall. 1 8 + 1 5 8 5 – 7 8 15 cm 18 cm ? Aini’s bear Caili’s bear 2 1 ? 78 cm 85 cm Activity 4 Unit 3 33 33 7 7 3 3 7 SMAB2A_03_pt1.indd 50 10/23/06 12:12:07 PM 51 3 Length: Solving Word Problems David uses two strings to tie a parcel. The first string is 28 cm long. The second string is 35 cm long. What is the total length of the two strings? The total length of the two strings is cm. Mr Hari bought a rope 150 m long. He used 95 m of it to fence his garden. What was the length of rope left? The length of rope left was m. 4 3 63 55 28 + 35 = 63 150 – 95 = 55 SMAB2A_03_pt1.indd 51 10/23/06 12:12:07 PM 52 3 Length: Solving Word Problems Mrs Li used 168 m of cloth to make school uniforms. She had 32 m of cloth left. How much cloth did she have at first? She had m of cloth at first. 5 Three flags, A, B and C are placed along a straight line. The distance between Flag B and Flag C is 28 m. The distance between Flag A and Flag B is 30 m longer than that between Flag B and Flag C. What is the distance between Flag A and Flag C? The distance between Flag A and Flag C is m. 6 A B C 200 86 168 + 32 = 200 28 + 30 = 58 58 + 28 = 86 SMAB2A_03_pt1.indd 52 10/23/06 12:12:08 PM 53 3 Length: Let’s Find Out Goldilocks and the Three Bears Goldilocks enters the bedroom of the three bears. She finds three beds. The length of the longest bed is 180 cm. Mother Bear’s bed is 30 cm shorter than Father Bear’s bed and 50 cm longer than Baby Bear’s bed. a) How long is Mother Bear’s bed? b) How long is Baby Bear’s bed? c) Goldilocks is 160 cm tall. Which bed fits her best? Why? Let’s Find Out Let’s Find Out 150 cm 100 cm Father Bear’s bed SMAB2A_03_pt1.indd 53 10/23/06 12:12:09 PM 54 Review 1 Count the tens and ones. Then fill in the missing numbers. 1 tens ones = a) tens ones = b) tens ones = c) Review 1 4 5 45 5 6 56 6 0 60 55 Review 1 In 496, the digit a) is in the ones place. b) is in the tens place. c) is in the hundreds place. 4 Fill in the missing numbers. a) 1 more than 54 is . b) 10 more than 68 is . c) 1 less than 45 is . d) 10 less than 93 is . 2 b) Write the numbers in words. 69 Forty-five Thirty-two 3 87 a) Write the numbers. 55 78 44 83 32 45 Sixty-nine Eighty-seven 6 9 4 56 Review 1 Fill in the missing numbers. a) 100 more than 123 is . b) 100 less than 635 is . c) 100 less than 656 is . d) 100 more than 379 is . Study each number pattern and fill in the missing numbers. Fill in the missing numbers. a) 400 + 20 + 5 = b) 600 + + 1 = 681 c) 900 + 90 + 9 = d) 200 + + 3 = 253 e) + 60 + 5 = 765 7 6 5 b) 332 432 532 a) 67 77 87 c) 384 374 364 d) 429 427 425 223 535 556 479 97 107 132 232 354 344 428 426 425 80 999 50 700 57 Review 1 Write the numbers. a) Three hundred and five b) Five hundred and twenty-four c) Seven hundred and fifty-nine d) Eight hundred and sixty-one 10 9 8 a) Arrange these numbers in order. Begin with the smallest number. 506 500 539 521 smallest Write the numbers in words. 308 a) b) c) d) 530 648 819 305 524 759 861 Three hundred and eight Five hundred and thirty Six hundred and forty-eight Eight hundred and nineteen 500 506 521 539 58 Review 1 b) Arrange these numbers in order. Begin with the greatest number. 708 718 780 735 greatest 11 12 Fill in the missing numbers. Arrange these three cards 2 1 3 to form: a) the greatest 3-digit number b) the smallest 3-digit number 87 80 7 80 + 7 = 87 – 7 = 7 + 80 = 87 – 80 = 7 more than 80 is . 7 less than 87 is . 780 735 718 708 3 2 1 1 2 3 87 80 87 7 87 80 59 Review 1 Add. a) 204 + 75 = b) 342 + 257 = 13 2 0 4 + 7 5 3 4 2 + 2 5 7 c) 654 + 18 = d) 357 + 64 = 6 5 4 + 1 8 3 5 7 + 6 4 e) 284 + 179 = f) 67 + 598 = + + g) 719 + 185 = h) 138 + 262 = + + 4 6 3 1 7 9 2 8 4 463 2 7 9 279 5 9 9 599 6 7 2 672 4 2 1 421 6 6 5 5 9 8 6 7 665 9 0 4 1 8 5 7 1 9 904 4 0 0 2 6 2 1 3 8 400 60 Review 1 Subtract. a) 198 – 52 = b) 364 – 143 = 14 1 9 8 – 5 2 3 6 4 – 1 4 3 c) 560 – 234 = d) 735 – 307 = 5 6 0 – 2 3 4 7 3 5 – 3 0 7 e) 613 – 264 = f) 750 – 268 = – – g) 832 – 748 = h) 400 – 265 = – – 2 6 4 6 1 3 349 146 221 326 428 482 8 4 7 4 8 8 3 2 84 1 3 5 2 6 5 4 0 0 135 2 6 8 7 5 0 1 4 6 2 2 1 3 2 6 4 2 8 3 4 9 4 8 2 61 Review 1 a) 345 + 123 + 66 = b) 45 + 236 + 459 = Add. 15 16 17 524 people were at the school carnival. 452 of them were children. The rest were adults. How many adults were there? There were adults. After spending $175 on a watch, Julie was left with $90. How much money did she have at first? She had $ at first. 3 4 5 1 2 3 + 6 6 4 5 2 3 6 + 4 5 9 534 740 265 72 5 3 4 7 4 0 $175 + $90 = $265 524 – 452 = 72 62 Review 1 18 19 Jane has 162 stickers. Meiling has 58 more stickers than Jane. How many stickers does Meiling have? Meiling has stickers. Mr Lin has $510. He spends $387 on a printer. How much money does he have left? He has $ left. 20 There are 528 Primary Two pupils in the school. There are 164 more Primary Two pupils than Primary One pupils. How many Primary One pupils are there? There are Primary One pupils. 220 123 364 162 + 58 = 220 $510 – $387 = $123 528 – 164 = 364 63 Review 1 21 There were 256 boys, 224 girls and 85 adults at a concert. a) How many children were there at the concert? b) How many more children than adults were there? a) There were children at the concert. b) There were more children than adults. 22 Fatimah prepared 370 sticks of mutton satay. She prepared 250 fewer sticks of mutton than chicken satay. a) How many sticks of chicken satay did she prepare? b) How many sticks of satay did she prepare altogether? a) She prepared sticks of chicken satay. b) She prepared sticks of satay altogether. 480 395 620 990 a) 256 + 224 = 480 b) 480 – 85 = 395 a) 370 + 250 = 620 b) 620 + 370 = 990 64 Review 1 23 Fill in the blanks. a) The length of the white tape is cm. b) The length of the black tape is cm. c) The total length of the two tapes is cm. d) The black tape is cm longer than the white tape. Which line is longer, PQ or RS? P Q R S Guess: is longer than . Check: PQ = cm RS = cm is longer than . 24 White tape Black tape 6 8 14 2 PQ RS 10 8 PQ RS 65 Review 1 a) Draw a straight line AB 5 cm long. b) Draw a straight line CD 3 cm longer than Line AB. 25 26 Fill in the blanks with cm or m. a) Daddy’s height is about 174 . b) The length of our school field is about 120 . c) The length of a pencil is about 18 . d) The width of the hall is about 20 . 27 a) My foot is about cm long. b) Mother’s foot is about cm long. c) My foot is cm shorter than Mother’s foot. My foot Mother’s foot cm m cm m 15 22 7 A B A B 66 Review 1 28 29 Mrs Crawford used 85 m of lace to make curtains. She had 28 m of lace left. How much lace did she have at first? She had m of lace at first. Isa uses two ribbons to tie presents. The first ribbon is 242 cm long. The second ribbon is 187 cm long. How much longer is the first ribbon than the second? The first ribbon is cm longer than the second ribbon. 29 Ahmad is 95 cm tall. Ban Lee is 16 cm taller than Ahmad. Charles is 10 cm shorter than Ban Lee. How tall is Charles? Charles is cm tall. 30 113 55 101 85 + 28 = 113 242 – 187 = 55 95 + 16 = 111 111 – 10 = 101