This lesson teaches the properties of operations on rational numbers such as addition, subtraction, multiplication, and division. It provides examples of applying properties like the commutative, associative, distributive, identity, and zero properties to simplify computations with rational numbers. Students are asked to use these properties to find missing numbers in examples and solve other exercises involving rational number operations. The key properties allow rational number calculations to be simplified and standardized.
1 of 5
More Related Content
Doc
1. Grade 7 Math LESSON 9: PROPERTIES OF THE OPERATIONS ON RATIONAL NUMBERS LEARNING GUIDE
AUTHOR: Gina Guerra 1
GRADE 7 MATH LEARNING GUIDE
Lesson 9: Properties of the Operations on Rational Numbers Time: 1.5 hours
Pre-requisite Concepts: Operations on rational numbers
About the Lesson: The purpose of this lesson is to use properties of operations on rational
numbers when adding, subtracting, multiplying and dividing rational numbers.
Objectives:
In this lesson, you are expected to
1. Describe and illustrate the different properties of the operations on rational
numbers.
2. Apply the properties in performing operations on rational numbers.
Lesson Proper:
I. Activity
Pick a Pair
2
14
3
5
0 1
13
40
13
12
1
3
3
20
From the box above, pick the correct rational number to be placed in the spaces provided to
make the equation true.
1. ___ = 6.
2. ____ + 7. =
3. = 0 8.
2
5
___
3
4
錚
錚
錚
錚
錚
錚 =
3
20
4. 1 x ____ = 9. = _____
5. + ____ = 10. = ____
Answer the following questions:
1. What is the missing number in item 1?
2. How do you compare the answers in items 1 and 2
3. What about item 3? What is the missing number?
4. In item 4, what number did you multiply with 1 to get ?
2. Grade 7 Math LESSON 9: PROPERTIES OF THE OPERATIONS ON RATIONAL NUMBERS LEARNING GUIDE
AUTHOR: Gina Guerra 2
5. What number should be added to in item 5 to get the same number?
6. What is the missing number in items 6 and 7?
7. What can you say about the grouping in items 6 and 7?
8. What do you think are the answers in items 8 and 9?
9. What operation did you apply in item 10?
Problem:
Consider the given expressions:
a.
b. =
* Are the two expressions equal? If yes, state the property illustrated.
PROPERTIES OF RATIONAL NUMBERS (ADDITION & MULTIPLICATION)
1. CLOSURE PROPERTY: For any two rational numbers. , their sum and
product is also rational.
For example:
a. =
b.
2. COMMUTATIVE PROPERTY: For any two rational numbers ,
i. =
ii. =
where a, b, c and d are integers and b and d are not equal to zero.
For example:
a.
b.
3. ASSOCIATIVE PROPERTY: For any three rational numbers
i.
3. Grade 7 Math LESSON 9: PROPERTIES OF THE OPERATIONS ON RATIONAL NUMBERS LEARNING GUIDE
AUTHOR: Gina Guerra 3
ii.
where a, b, c, d, e and f are integers and b, d and f are not equal to zero.
For example:
a.
b.
4. DISTRIBUTIVE PROPERTY of multiplication over addition for rational numbers.
If are any rational numbers, then
For example:
5. DISTRIBUTIVE PROPERTY of multiplication over subtraction for rational numbers.
If are any rational numbers, then
For example:
6. IDENTITY PROPERTY
Addition: Adding 0 to a number will not change the identity or value of that number.
+ 0 =
For example:
Multiplication: Multiplying a number by 1 will not change the identity or value of that
number.
For example:
7. ZERO PROPERTY OF MULTIPLICATION: Any number multiplied by zero equals 0,
i. e.
For example:
II. Question to Ponder (Post-Activity Discussion)
Let us answer the questions posed in the opening activity.
4. Grade 7 Math LESSON 9: PROPERTIES OF THE OPERATIONS ON RATIONAL NUMBERS LEARNING GUIDE
AUTHOR: Gina Guerra 4
1. What is the missing number in item1? 損
2. How do you compare the answers in items 1 and 2? 損 The answer is the same, the
order of the numbers is not important.
3. What about item 3? What is the missing number? 損 The missing number is 0. When
you multiply a number with zero the product is zero.
4. In item 4, what number did you multiply with 1 to get ? 損 When you multiply a
number by one the answer is the same.
5. What number should be added to in item 5 to get the same number? 損 0, When you
add zero to any number, the value of the number does not change.
6. What do you think is the missing number in items 6 and 7?損
7. What can you say about the grouping in items 6 and 7? 損 The groupings are different
but they do not affect the sum.
8. What do you think are the answers in items 8 and 9? 損 The answer is the same in both
items, .
9. What operation did you apply in item 10? 損 The Distributive Property of
Multiplication over Addition
III. Exercises:
Do the following exercises. Write your answer in the spaces provided.
A. State the property that justifies each of the following statements.
1. _________________________
2. 1 = ____________________________
3. ___________________
4. ___________________________
5.
2
7 + 1
5 + 2
3( )1 = 2
7 + 1
5 + 2
3( ) ___________________________
5. Grade 7 Math LESSON 9: PROPERTIES OF THE OPERATIONS ON RATIONAL NUMBERS LEARNING GUIDE
AUTHOR: Gina Guerra 5
6. ______________________________________
7.
1
2 + 5
6 = 4
3 _________________________________
8. = _______________________
9.
1
4
___________________________
10.
2
15 5
7( ) 0 = 0______________________________________
B. Find the value of N in each expression
1. N +
2. =
3. = +
4. 0 + N =
6. N =
7.
8. = N
Summary
This lesson is about the properties of operations on rational numbers. The properties are
useful because they simplify computations on rational numbers. These properties are true under
the operations addition and multiplication. Note that for the Distributive Property of
Multiplication over Subtraction, subtraction is considered part of addition. Think of subtraction
as the addition of a negative rational number.