Even & Odd Numbers — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. When you add two odd numbers, the answer is always even.
Each odd number has one extra piece, and the two extras combine into a new pair. For example, 3 + 5 = 8, which is even.
2. The next even number after 38 is 40.
Even numbers step up by 2, so after 38 you skip the odd 39 and reach 40. Both 38 and 40 end in an even digit.
3. The number 29 is odd because it ends in 9.
9 is one of the odd digits (1, 3, 5, 7, 9), so 29 is odd. Splitting 29 into two groups leaves 14 in one and 15 in the other.
4. If you subtract 1 from an odd number, you get an even number.
Taking away the one extra piece from an odd number leaves only pairs, which is the definition of even. For example, 9 - 1 = 8, which is even.
5. Count by 2s starting from 1: 1, 3, 5, 7, 9.
Each step adds 2, so 7 plus 2 lands on 9. Counting by 2s from 1 lists every odd number in order.
6. The even number between 15 and 19 is 16.
Between 15 and 19 the numbers are 16, 17, and 18. Both 16 and 18 are even, but the one that comes right after 15 is 16.
7. The number 50 is even because it ends in 0.
0 is one of the even digits, so every number ending in 0 is even. 50 also splits into two equal groups of 25.
8. There are 5 odd numbers between 1 and 10.
From 1 to 10 the odd numbers are 1, 3, 5, 7, and 9. Count them and you get 5 odd numbers in all.
9. An odd number plus an odd number gives an even number.
The two leftover pieces from each odd number pair up together to make the total even. For example, 7 + 5 = 12, which is even.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Even ending in 2
→ 32
40
Odd ending in 7
→ 17
17
Even ending in 0
→ 40
32
Odd ending in 1
→ 21
21
Correct matches: Even ending in 2 → 32; Odd ending in 7 → 17; Even ending in 0 → 40; Odd ending in 1 → 21.