12 and 6 are both even numbers.
Here are 5 such pairs of even numbers and their sums.
6 + 8 = 14
4 + 8 = 12
2 + 10 = 12
4 + 12 = 16
10 + 8 = 18
(Answer may vary)
We observe that when we add two even numbers, the sum is always an even number.
Rule: Even number + even number – even number.
(b) 13 and 9 are a pair of odd numbers. Choose 5 such pairs of odd numbers. Add the numbers in each of the pairs.
Solution:
13 and 9 are both odd numbers.
Here are 5 such pairs of odd numbers and their sums.
19 + 9 = 28
11 + 7 = 18
5 + 15 = 20
13 + 7 = 20
5 + 19 = 24
(Answer may vary)
We observe that when we add two odd numbers, the sum is always an even number.
Rule: Odd number + odd number = even number
(c) 7 and 12 are a pair of odd and even numbers. Choose 5 such pairs of odd and even numbers. Add the numbers in each of the pairs.
Solution:
7 and 12 are pair of odd and even numbers. Here are 5 such pairs of odd and even numbers and their sum.
3 + 4 = 7
9 + 12 = 21
12 + 11 = 23
7 + 10 = 17
11 + 6 = 17
We observe that when we add an odd number and an even number, the sum is always an odd number.
Rule: Odd number + even number = odd number
or Even number + odd number = odd number.
NCERT Textbook Pages 54-55
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