Even & Odd Numbers — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Which pair of numbers are both odd?
A) 12 and 14
B) 11 and 23
C) 6 and 18
D) 20 and 30
11 ends in 1 and 23 ends in 3, and both 1 and 3 are odd digits, so both numbers are odd. Any other pair would include at least one even number.
2. What happens when you add an even and an odd number?
A) Always even
B) Always odd
C) Always zero
D) Could be either
The even number pairs up perfectly, but the odd number brings one leftover piece that cannot pair. That stray piece makes the sum odd every time, like 4 + 3 = 7.
3. What completes the pattern: 5, 10, 15, 20, ___?
A) 22
B) 24
C) 25
D) 30
Each number in the pattern is 5 more than the one before it, so 20 + 5 = 25. This is skip counting by 5s.
4. Sarah has 27 beads. Can she split them into 2 equal groups?
A) Yes, 27 is even
B) No, 27 is odd
C) Yes, 27 is big
D) No, too many
27 ends in 7, which is an odd digit, so it cannot split evenly. One group would have 13 beads and the other 14, leaving 1 bead unmatched.
Part B: Fill in the Blank
Write the correct answer on each line.
1. The sum of 13 and 15 is 28, which is even.
Add 13 + 15 column by column to get 28. Two odd numbers always add to an even number because their leftover pieces pair up.
2. If you subtract an odd from an even, the result is always odd.
Taking an odd amount from an even number breaks one of the pairs, leaving a stray piece. For example, 10 - 3 = 7, which is odd.
3. The largest even number less than 50 is 48.
49 ends in 9 and is odd, so step back one more to 48, which ends in the even digit 8. 48 is the closest even number under 50.
4. Between 30 and 40, there are 5 odd numbers.
The odd numbers from 30 to 40 are 31, 33, 35, 37, and 39. Counting those gives 5 odd numbers in that range.
5. Double any whole number always gives an even number.
Doubling means making two equal groups, and any number that fits into two equal groups is even. For example, doubling 7 gives 14, which is even.