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SAI International School

Class : VII

Mathematics

Chapter - 9 – Rational Number

Lesson Note – 9.3

Subtopics:

 Addition operation on rational numbers
 Additive inverse
 Subtraction

1. Addition:
 Addition of two rational numbers with the same denominator

1 2
Example: Add and
5 5
Solution:

 We can add it using a number line.

On the number line we have to move right from 0 to 1/5 units and then move 2/5 units

more to the right.

 If we have to add two rational numbers whose denominators are same then we simply
add their numerators and the denominator remains the same.

3 7
Example : Add and .
11 11
Solution: As the denominator is the same, we can simply add their numerator.