Textbook
Prathomsuksa 4 © Pelangi Publishing (Thailand) Co., Ltd. 2022 All rights reserved. No part of this publication may be reproduced, stored in any retrieval system or transmitted in any form or by any means without permission of Pelangi Publishing (Thailand) Co., Ltd. 2022
BDRC304031_GoGetMaths TB Prelimpage P4.indd 1
885-87220-0359-3 First Published 2022
19/1/2565 BE 09:22
Contents Chapter 1
Numbers Lesson 1 Lesson 2 Lesson 3
Chapter 2
Chapter 3
Chapter 4
Chapter 5
2 7 12
20
Lesson 1 Lesson 2 Lesson 3 Lesson 4
21 24 27 29
Addition Subtraction Finding the unknowns Word problems
Multiplication and division
33
Lesson 1 Lesson 2 Lesson 3 Lesson 4 Lesson 5
34 41 47 49 53
Multiplication Division Finding the unknowns Word problems Number patterns
Mixed operations
60
Lesson 1 Lesson 2
61 63
Order of operations Word problems
Fractions
68 Types of fractions Equivalent fractions Comparing and ordering fractions Addition and subtraction of fractions Word problems
Time Lesson 1 Lesson 2 Lesson 3 Lesson 4
SG Maths TB P4 page i-iv.indd 3
Counting beyond 100,000 Comparing and ordering numbers Estimation
Addition and subtraction
Lesson 1 Lesson 2 Lesson 3 Lesson 4 Lesson 5
Chapter 6
1
69 75 80 85 90
93 Units of time Comparing duration of events Word problems Schedules
94 99 101 104
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Chapter 7
Decimals Lesson 1 Lesson 2
Chapter 8
Chapter 9
Understanding decimals Comparing and ordering decimals
110 123
Addition and subtraction of decimals
129
Lesson 1 Lesson 2 Lesson 3
130 137 142
Chapter 11
Addition of decimals Subtraction of decimals Word problems
Geometry Lesson 1 Lesson 2
Chapter 10
109
148 Geometric terms Angles
149 152
Squares and rectangles
164
Lesson 1 Lesson 2 Lesson 3 Lesson 4 Lesson 5 Lesson 6
165 169 175 179 183 187
Properties of squares and rectangles Drawing squares and rectangles Perimeter Area Perimeter and area of composite figures Word problems
Two-way tables and bar graphs
190
Lesson 1 Lesson 2
191 195
Two-way tables Bar graphs
Computational thinking
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203
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The big idea
Illustrates a scenario through which students can connect to the Chapter 1 chapter. Numbers more than 100,000
Computational thinking
Special Features
Introduces a new approach for solving complex problems with confidence.
This bee farm has about 950,000 bees. Is that a lot?
Lesson 1
Counting numbers more than 100,000
Lesson 2
Comparing and ordering numbers
Lesson 3
Estimation
Starting point
Provides questions to initiate thinking and jump-start learning.
Computational thinking is not about programming a computer or thinking like a computer. It is rather a set of systematic approaches to solving problems. Then, we can present the solutions in a way a computer or a human or both can understand. There are four skills or elements in computational thinking.
Decomposition
Lesson 1
Breaking a complex problem into manageable, smaller problems
Types of fractions
Starting point
1 12
Look at these fractions. Are they the same? What does each mean?
3 2
?
Algorithms
1 2
Learning to know
?
Abstraction
Focusing on relevant information, and removing irrelevant information
Proper fractions and improper fractions
1 2
Introduces new concepts using the CPA approach with engaging illustrations.
Numerator With this new approach, we will be able to tackle unfamiliar and complex problems with confidence. It trains us to analyze information and deal with problems across disciplines. It will help us see a relationship between the school and the outside world.
Denominator
5 6
6 7
Computational thinking |
The fractions shown above are proper fractions. A proper fraction is a fraction where the numerator is smaller than the denominator.
Thinking corner
Challenges students with unconventional questions to develop higher-order thinking skills.
Identifying similarities and differences, and observing similar patterns
Developing a set of step-by-step solution
? Learning to know
Pattern recognition
203
Fun with Maths!
Are 2 , 3 and 5 proper fractions? 2 3 5 Chapter 5 | 69
Allows students to explore mathematical concepts actively either as an individual or in groups.
1. Work in pairs. 2. Write an improper fraction on a card and its equivalent mixed number on another card. 3. Make 10 sets of such cards. 4. Ask your partner to check the cards to ensure the improper fractions and their mixed numbers are written correctly. 5. Shuffle the cards and place them face down in rows. 6. Turn over any two cards. 7. If the cards match, keep the cards. Repeat step 6. 8. If the cards do not match, it is your partner’s turn. 9. The person with more cards wins.
1. Circle the improper fractions. Cross the mixed numbers. 1 6
7 2 6 2
4 10 3 15
2 7
1 43 8 8
5 6 11
2. Convert each improper fraction to a mixed number. 4 9 15 (b) 4 = (c) 2 = (a) 3 =
23 (d) 7 =
3. Convert each mixed number to an improper fraction. 2 3 3 (a) 1 3 = (b) 1 5 = (c) 2 6 =
4 (d) 4 9 =
Try this
Provides various exercises to immediately evaluate students’ understanding.
74 | Mathematics Prathomsuksa 4
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Chapter 1
Numbers
This bee farm has about 950,000 bees. Is that a lot?
Sg Maths TB P4 Chpt1-4.indd 1
Lesson 1
Counting beyond 100,000
Lesson 2
Comparing and ordering numbers
Lesson 3
Estimation
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Counting beyond 100,000
Lesson 1 Starting point
It is estimated that by the end of 2023, 10,899,698 people will be living in Bangkok. How do you read this number?
Learning to know
Counting on from 100,000
100,000
100,000
100,000
100,000
100,000
100,000
100,000
100,000
100,000
100,000
1,000,000
10 hundred thousands make 1 million.
1,000,000
1,000,000
1,000,000
1,000,000
1,000,000
1,000,000
1,000,000
1,000,000
1,000,000
1,000,000
10,000,000
10 millions make 1 ten million.
10,000,000
10,000,000
10,000,000
10,000,000
10,000,000
10,000,000
10,000,000
10,000,000
10,000,000
10,000,000
100,000,000
10 ten millions make 1 hundred million. 2 | Mathematics Prathomsuksa 4
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100,000
10,000
1,000
1,000
100
100
10
1
100,000
10,000
1,000
1,000
100
100
10
1
100,000
10,000
1,000
100
100
10
1
10,000
1,000
100
10
1
1,000
100
10
1
๓๔๗,๘๕๕
347,855 ( ) Three hundred and forty-seven thousand eight hundred and fifty-five 10,000
1,000
100
100
10
1
100,000
1,000
100
100
10
1
100,000
1,000
100
100
10
1
100,000
1,000
100
100
1,000
100
1,000,000
100,000
1,000,000
1 1
๒,๔๑๕,๙๓๕
2,415,935 ( ) Two million four hundred and fifteen thousand nine hundred and thirty-five
100
10
1,000,000
100
10
1,000,000
100
10,000,000
1,000,000
10,000,000
100,000
1,000,000
๒๔,๑๐๐,๓๒๐
24,100,320 ( ) Twenty-four million one hundred thousand three hundred and twenty Chapter 1 | 3
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What do 10 hundred millions make? How many zeros are there?
Place values
Learning to know
532,468 1
1
10
1
1
100
10
1
1
100
10
1
10
1
100,000
10,000
1,000
100
10
100,000
10,000
1,000
100
100,000
10,000
100,000 100,000
Hundred thousands (HTh)
Ten thousands (TTh)
5
3
Thousands Hundreds (Th) (H) 2
4
10
Tens (T)
Ones (O)
6
8
532,468 = 5 hundred thousands 3 ten thousands 2 thousands 4 hundreds 6 tens 8 ones 532,468 = 500,000 + 30,000 + 2,000 + 400 + 60 + 8 The digit 5 in 532,468 is in the hundred thousands place. Its value is 500,000. The digit 3 in 532,468 is in the ten thousands place. Its value is 30,000. The digit 2 in 532,468 is in the thousands place. Its value is 2,000. The digit 4 in 532,468 is in the hundreds place. Its value is 400. The digit 6 in 532,468 is in the tens place. Its value is 60. The digit 8 in 532,468 is in the ones place. Its value is 8. 4 | Mathematics Prathomsuksa 4
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8,751,349 Millions (M) 8
Thousands Hundreds Ten Hundred (Th) (H) thousands thousands (TTh) (HTh) 7
5
1
3
Tens (T)
Ones (O)
4
9
8,751,349 = 8 millions 7 hundred thousands 5 ten thousands 1 thousand 3 hundreds 4 tens 9 ones 8,751,349 = 8,000,000 + 700,000 + 50,000 + 1,000 + 300 + 40 + 9 The digit 8 in 8,751,349 is in the millions place. Its value is 8,000,000. The digit 7 in 8,751,349 is in the hundred thousands place. Its value is 700,000. The digit 5 in 8,751,349 is in the ten thousands place. Its value is 50,000. The digit 1 in 8,751,349 is in the thousands place. Its value is 1,000. The digit 3 in 8,751,349 is in the hundreds place. Its value is 300. The digit 4 in 8,751,349 is in the tens place. Its value is 40. The digit 9 in 8,751,349 is in the ones place. Its value is 9.
1. Work in pairs. 2. Write a number with more than 5 digits on a piece of paper. 3. Show it to your partner. 4. Your partner will read out the number and say the value of each digit in the number. The value of the digit 4 is 400,000.
5. Switch roles and repeat. Chapter 1 | 5
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1. Count. Write in numerals and words. 10
1
1,000 1,000
10
1
10,000
1,000 1,000
10
1
10,000
1,000 1,000
10
1
10,000
1,000
10
1,000,000
100,000
10,000 10,000
1,000 1,000
1,000,000
100,000
10,000 10,000
1,000,000
100,000 100,000
Thai numerals:
100
Hindu-Arabic numerals:
Words: 2. Fill in the blanks. (a) 874,123 = 800,000 + 70,000 + (b)
= 200,000 + 60,000 + 3,000 + 700 + 30 + 4
(c) 4,624,382 = (d)
+ 100 + 20 + 3
+ 600,000 + 20,000 + 4,000 + 300 + 80 + 2
= 1,000,000 + 300,000 + 70,000 + 2,000 + 500 + 50 + 4
3. Fill in the blanks. 7,364,159 (a) The digit 7 in 7,364,159 is in the
place. Its value is
.
(b) The digit 3 in 7,364,159 is in the
place. Its value is
.
(c) The digit 6 in 7,364,159 is in the
place. Its value is
.
(d) The digit 4 in 7,364,159 is in the
place. Its value is
.
(e) The digit 1 in 7,364,159 is in the
place. Its value is
.
(f) The digit 5 in 7,364,159 is in the
place. Its value is
.
(g) The digit 9 in 7,364,159 is in the
place. Its value is
.
6 | Mathematics Prathomsuksa 4
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Lesson 2 Comparing and ordering numbers Starting point
765,897
There are so many digits in these two numbers. How do we know which is the greater number?
Learning to know
7,025,674
Comparing numbers
Compare 5,741,354 and 597,056. Compare the number of digits in each number. 5,741,354 has 7 digits. 597,056 has 6 digits. The number with more digits is the greater number. So, 5,741,354 is greater than 597,056. 5,741,354 > 597,056
or
5,741,354
597,056
597,056 is smaller than 5,741,354. 597,056 < 5,741,354
Which is greater, 7,541,240 or 8,640,425? 7,541,240
8,640,425
M
HTh
TTh
Th
H
T
O
7
5
4
1
2
4
0
M
HTh
TTh
Th
H
T
O
8
6
4
0
4
2
5
Compare the millions. 8 is greater than 7. So, 8,640,425 is greater than 7,541,240. 8,640,425 > 7,541,240 Chapter 1 | 7
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