BCRB294038
ISBN 978-616-541-303-9
,!7IG1G5-ebdadj! Pri Edu Maths TB Thai P4_CVR.indd 1
Based on the Basic Education Curriculum B.E. 2551 (Revised Edition B.E. 2560) 3/7/18 2:14 PM
© Pelangi Publishing (Thailand) Co., Ltd. 2018 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. 2018
Pri Edu Maths TB Thai P4_TP.indd 1
ISBN 978-616-541-303-9 First Published 2561
3/7/18 11:24 AM
Contents Chapter 1
Numbers Greater than 100,000
B Multiplying by 1-digit numbers ............. 40 1
C Multiplying by 2-digit numbers ............. 42
A Reading and writing numbers greater than 100,000 ........................... 2
D Multiplying by 3-digit numbers ............. 45
B Place value, digit value and using zero as a placeholder .......................... 5 C Writing numbers in expanded form ..... 7 D Comparing and ordering numbers....... 8 E
Addition and Subtraction
Solving multiplication word problems.............................................. 48
F
Creating multiplication word problems.............................................. 50
Chapter 4
Estimation............................................ 12
Chapter 2
E
Division
51
A Division by 2-digit divisors ................... 52 15
B Solving division word problems ........... 56
A Addition ............................................... 16
C Creating division word problems ......... 58
B Subtraction .......................................... 22
Chapter 5
C Combined operations .......................... 26
Combined Operations
D Solving word problems ........................ 28 E
A Combined operations .......................... 60
Creating word problems ...................... 34
Chapter 3 Multiplication
59
B Using combined operations to solve word problems ........................... 63 C Creating word problems involving combined operations ........................... 65
37
A Properties of multiplication .................. 38
II
Chapter 6 Fractions
Chapter 9
68
Points, Lines, Line Segments, Rays and Planes
A Proper fractions, improper fractions and mixed numbers ............................. 69
126
A Points .................................................. 127
B Equivalent fractions ............................. 75
B Lines .................................................... 128
C Comparing and ordering fractions ....... 76
C Line segments ..................................... 129
D Operations involving fractions ............. 83
D Rays .................................................... 131
E
E
Solving word problems involving fractions ............................................... 90
Chapter 7 Decimals
Planes ................................................. 132
Chapter 10 Angles
92
135
A Types of angles ................................... 136
A Writing and naming decimals .............. 93
B Measuring angles ................................ 140
B Place values and digit values of digits in decimals .......................................... 98
C Drawing angles.................................... 145
C Writing decimals in expanded form ..... 99
Chapter 11
D Equivalent decimals ............................ 100 E
Comparing and ordering decimals ...... 101
F
Operations involving decimals............. 104
A Types of rectangles ............................. 151
G Solving word problems involving addition and subtraction of decimals ... 109
B Drawing rectangles.............................. 153
Chapter 8
D Area of a rectangle .............................. 157
Time
Rectangles
150
C Perimeter of a rectangle ...................... 155
E
111
A Relationship between units of time...... 112
Solving word problems involving perimeter and area of rectangles ........ 160
Chapter 12
B Duration of time ................................... 116 C Schedule (timetables).......................... 118
Bar Charts and Two-way Tables
164
D Schedule (program)............................. 120
A Reading and drawing bar charts ......... 165
E
B Two-way tables.................................... 169
Solving word problems involving time...................................................... 122
III
Special features in this book
Provides practical activities to enhance students’ interest, knowledge and experience in learning mathematics.
Encourages students to recall and list down what they know about the topic.
Provides an activity that engages in the application of knowledge of scientists, mathematicians and engineers.
Provides the learning outcomes of the lesson and encourages students to share what they want to learn in the topic.
Challenges students with questions that promote higher thinking skills.
4C’s of the 21st Century 4C’s The Skills are Communication Sharing thoughts, questions, ideas & solutions.
Helps students to identify what they have learned at the end of the lesson.
Collaboration Working together to reach a goal. Putting talent, expertise and smarts to work. Provides exercises to reinforce students’ grasp of mathematical concepts.
Critical Thinking Looking at problems in a new way and linking learning across subjects & disciplines. Creativity Trying new approaches to get things done equals innovation & invention.
IV
1
Chapter
Numbers Greater than 100,000 The area of Thailand is 513,115 square kilometers. How do you read this number?
What do I know about numbers greater than 100,000? 1. 2. 3. What else do I want to know about numbers greater than 100,000? 1. How do I read, write and count Hindu-Arabic numerals and Thai numerals greater than 100,000? 2. How do I determine the place values and digit values of digits in numbers greater than 100,000? 3. How do I write the numbers greater than 100,000 in expanded form? 4. How do I compare and order numbers greater than 100,000? 5. How do I estimate numbers greater than 100,000? 6.
A
Reading and writing numbers greater than 100,000
100,000
100,000
100,000
100,000
100,000
100,000
100,000
100,000
100,000
100,000
10 one hundred thousands
1,000,000
One million
๑,๐๐๐,๐๐๐
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 one millions
10,000,000
Ten million
๑๐,๐๐๐,๐๐๐
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
10 ten millions
100,000,000
One hundred million
2
MATHEMATICS Prathomsuksa
4
๑๐๐,๐๐๐,๐๐๐
In order to read and write numbers in words, we must know the place values of its digits.
568,523
Hundred Ten Thousands Hundreds thousands thousands 5
6
8
5
Tens
Ones
2
3
568,523 is read as five hundred and sixty-eight thousand five hundred and twenty-three. 785,125,300 Hundred Ten Hundred Ten Millions Thousands Hundreds Tens Ones millions millions thousands thousands 7
8
5
1
2
5
3
0
0
785,125,300 is read as seven hundred and eighty-five million one hundred and twenty-five thousand and three hundred.
How do we write three hundred and fortyfive thousand two hundred and fifty-eight in numerals?
Hundred Ten Thousands Hundreds thousands thousands 3
4
5
2
Tens
Ones
5
8
Three hundred and forty-five thousand two hundred and fifty-eight is written as 345,258.
Numbers Greater than 100,000
3
How do we write four hundred and ninety-seven million six hundred thousand eight hundred and seventeen in numerals? Hundred Ten Hundred Ten Millions Thousands Hundreds Tens Ones millions millions thousands thousands 4
9
7
6
0
0
8
1
7
Four hundred and ninety-seven million six hundred thousand eight hundred and seventeen is written as 497,600,817. M AT H T I P S When writing a number that has more than three digits, a comma “,” is inserted before every three digits counting from the rightmost digit, that is the digit in the ones place, to enable easy reading. Examples: (a) 15,247 (c) 646,380,201
(b) 3,657,999 (d) 8,791,046,352
1. Write the following in numerals. (a) Two hundred and fifty-two thousand eight hundred and seventy-four (b) Forty-five million one hundred and thirtynine thousand two hundred and fifty 2. Insert commas in the right places in the following numbers. Then, write the numbers in words. (a) 235450
:
(b) 8745105 : (c) 78402153 :
4
MATHEMATICS Prathomsuksa
4
B
Place value, digit value and using zero as a placeholder
Place value and digit value Do you know the location of Thailand and its area in square kilometers?
Thailand is located on the Indochina Peninsula in Southeast Asia. The area of Thailand is about 513,115 square kilometers. Thailand is the third largest country in the region.
We can use a table like the one shown below to present the value of each digit in 513,115. Place Hundred Ten Thousands Hundreds Tens value thousands thousands Digit
5
1
3
Digit 5 × 100,000 1 × 10,000 3 × 1,000 value = 500,000 = 10,000 = 3,000 From the table, we find that
5 in the hundred thousands place
1
1
1 × 10 5 × 1
= 100
= 10
500,000
has a digit value of
3,000
1 in the hundreds place
has a digit value of
5 in the ones place
=5
has a digit value of
has a digit value of
1 in the tens place
5
1 × 100
1 in the ten thousands place 3 in the thousands place
Ones
has a digit value of
10,000
100
has a digit value of
10
5
Do you notice that in 513,115, there are two number 5s in different place values? Therefore, the two 5s have different digit values.
Numbers Greater than 100,000
5
Using zero as a placeholder “0” is used as a placeholder in a number so that the non-zero digits in the number can be positioned in the correct places. For example, consider the following number.
3,405 The tens place in the number 3,405 has a zero in it. This means that the tens place in 3,405 has no digit value. However, the “0” must be put there so that the non-zero numbers, “3”, “4” and “5” are correctly positioned in their respective places.
1. State the place value and digit value of each underlined digit. Number
Place value
Digit value
3,549,000 4,879,368 61,028,174 15,236,997 789,300,208 479,655,178 2. State the place value occupied by 0 in each number.
6
(a) 599,071
(b) 1,807,993
(c) 401,478,744
(d) 520,789,146
MATHEMATICS Prathomsuksa
4
C Writing numbers in expanded form Writing a number in expanded form is writing the number in the form of addition.
56,589,015 Place Ten value millions Digit
Millions
5
6
Hundred Ten Thousands Hundreds Tens Ones thousands thousands 5
Digit 50,000,000 6,000,000 500,000 value
8
9
0
1
5
80,000
9,000
0
10
5
In expanded form, 56,589,015 is written as 50,000,000 + 6,000,000 + 500,000 + 80,000 + 9,000 + 10 + 5
Write in expanded form. 1. 765,158
=
2. 6,250,369
=
3. 258,364,037 =
Numbers Greater than 100,000
7
D Comparing and ordering numbers Comparing numbers Yesterday I read a book about Southeast Asia. I found out that Laos has an area of 236,800 square kilometers. Does that mean Laos is bigger than Thailand? Thailand has an area of 513,115 square kilometers. How do we compare the two numbers?
Steps: 1. First, compare the numbers of digits. The number with more digits is the greater number. 2. If the numbers of digits are equal, then compare the digits of both numbers starting from the leftmost place. 3. Use a place value table to compare the digits of both numbers.
Compare 5,367,890 with 687,324. Which number is greater? Millions
Hundred Ten Thousands Hundreds Tens Ones thousands thousands
5
3
6
7
8
9
0
6
8
7
3
2
4
5,367,890 has 7 digits. 687,324 has 6 digits. So, 5,367,890 is greater than 687,324.
8
MATHEMATICS Prathomsuksa
4
Which number is greater, 3,209,765 or 3,208,413? Millions
Hundred Ten Thousands Hundreds Tens Ones thousands thousands
3
2
0
9
7
6
5
3
2
0
8
4
1
3
144444424444443 9 is greater than 8.
Both numbers have the same digits.
Both numbers have the same number of digits. Both numbers have the same digits in the millions, hundred thousands and ten thousands places. Compare the thousands : 9,000 > 8,000. So, 3,209,765 is greater than 3,208,413. Now, let’s compare the areas of Laos and Thailand.
Area Hundred Ten Thousands Hundreds Tens Ones thousands thousands Country Laos
2
3
6
8
0
0
Thailand
5
1
3
1
1
5
Both numbers have the same number of digits. In the hundred thousands place : 2 in the number 236,800 has a digit value of 200,000. 5 in the number 513,115 has a digit value of 500,000. 200,000 < 500,000 Therefore, 236,800 is smaller than 513,115. This means that Laos has a smaller area than Thailand.
Numbers Greater than 100,000
9
Ordering numbers Arrange the numbers in ascending order. 236,258
238,420
89,540
1,257,600
Compare the number of digits in each number. 89,540 has only five digits. The rest have more than five digits. So, 89,540 is the smallest. 1,257,600 has seven digits. 236,258 and 238,420 have six digits. So, 1,257,600 is the greatest. Compare the hundred thousands and ten thousands of 236,258 and 238,420. Both have the same digits. Compare the thousands of 236,258 and 238,420. 6 thousands is smaller than 8 thousands. So, 236,258 is smaller than 238,420. In ascending order:
89,540,
236,258,
238,420,
smallest
1,257,600 greatest
Arrange the numbers in descending order. 258,650
21,258,360
28,369,124
28,569,140
Compare the number of digits in each number. 258,650 has six digits. The rest have eight digits. So, 258,650 is the smallest. Compare the ten millions of 21,258,360, 28,369,124 and 28,569,140. They have the same digit.
10
MATHEMATICS Prathomsuksa
4
BCRB294038
ISBN 978-616-541-303-9
,!7IG1G5-ebdadj! Pri Edu Maths TB Thai P4_CVR.indd 1
Based on the Basic Education Curriculum B.E. 2551 (Revised Edition B.E. 2560) 3/7/18 2:14 PM