Even & Odd Numbers — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Which sum gives an odd number?
A) 4 + 6
B) 8 + 12
C) 7 + 10
D) 2 + 14
7 is odd and 10 is even, and odd plus even always gives an odd sum. Doing the math, 7 + 10 = 17, which ends in 7 and is odd.
2. Jake says all numbers ending in 5 are odd. Is he correct?
A) No, some are even
B) Yes, he is correct
C) Only under 50
D) Only over 10
5 is one of the five odd digits (1, 3, 5, 7, 9), so every number ending in 5 like 15, 25, or 95 is odd. Jake's rule works for every whole number.
3. Which number is even and between 40 and 45?
A) 41
B) 43
C) 42
D) 45
The numbers between 40 and 45 are 41, 42, 43, and 44. 42 and 44 are even, but 42 ends in 2 and is the smaller even number right after 40.
4. Emma adds two odd numbers. Her answer will always be:
A) Odd
B) Even
C) Zero
D) Greater than 20
Each odd number has one extra piece that won't pair up, but when two odd numbers meet, those two strays pair with each other. That's why odd + odd = even, like 5 + 7 = 12.
Part B: Fill in the Blank
Write the correct answer on each line.
1. The sum of 18 and 7 is 25, which is odd.
Add 18 + 7 to get 25, which ends in 5 and is odd. Even plus odd always gives an odd sum because the odd number brings one extra piece.
2. If you add 2 to any odd number, the result is always odd.
Adding 2 jumps you ahead by exactly one odd or even step, so odd stays odd. For example, 5 + 2 = 7, and both are odd.
3. The smallest odd number greater than 40 is 41.
The next number after 40 is 41, which ends in 1 and is odd. Since 40 is even, the very next number is always odd.
4. Between 20 and 30, the even numbers are 20, 22, 24, 26, and 28.
Each even number is 2 more than the one before, so 26 + 2 = 28. 28 ends in 8, and the next even number would be 30.
5. An even number minus an even number is always even.
Both numbers are made of pairs, so taking pairs away still leaves pairs behind. For example, 12 - 4 = 8, which is even.