Work through the levels in order. Type your answer and press Check — open the worked solution if you get stuck. Answers like -6, 3/4 or 0.25 are typed exactly as shown. A ⭐ Bonus Challenge at the end is extra credit — skip it if the rest was hard work.
Level 1 · Warm-up
1 Is 4736 odd or even?
Show worked solution
Only the ones digit matters. It is 6, which is even, so 4736 is even.
2 Without adding them: is 253 + 148 odd or even?
Show worked solution
253 is odd and 148 is even. Odd + even is always odd. (It is 401.)
3 Is the answer to 6 × 7 odd or even?
Show worked solution
Multiplying by an even number always gives an even answer: 6 × 7 = 42, which is even.
Level 2 · Core
4 An odd number is multiplied by another odd number. Is the answer odd or even?
Show worked solution
3 × 5 = 15, 7 × 9 = 63 — always odd. Odd × odd is the only multiplication that never gives an even answer.
5 I am odd, I am between 340 and 350, and my digits add to 10. What number am I?
Show worked solution
The number is 34_, so 3 + 4 = 7 and the ones digit must be 3 to reach 10. 343 is odd, so it is 343.
6 Three odd numbers are added together. Is the total odd or even?
Show worked solution
The first two odds make an even, and even + odd is odd. So the total is always odd (for example 1 + 3 + 5 = 9).
Level 3 · Challenge
7 The sum of two numbers is odd, and one of them is even. Is the other one odd or even?
Show worked solution
Even + even is even, so that cannot give an odd total. The other number must be odd.
8 How many odd numbers are there between 200 and 220, not counting 200 and 220?
Show worked solution
They run 201, 203, … 219. That is 10 odd numbers.
9 An even number is added to an odd number, and the total is then doubled. Is the result odd or even?
Show worked solution
Even + odd is odd, but doubling any whole number always gives an even answer. So the result is even.
⭐ Bonus Challenge · only if the rest felt easy
10 An odd number is added to another odd number, and the answer is then multiplied by 3. Is the final answer odd or even?
Show worked solution
Odd + odd is always even (3 + 5 = 8). An even number times any number stays even (8 × 3 = 24). So the answer is always even.