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 I am odd, bigger than 20, smaller than 26. Who am I? (there are three — give any one)
Show worked solution
21, 23 or 25 all fit — real puzzles add one more clue to leave just one!
2 Ana, Ben, Cara have a dog, cat, bird. Ana is allergic to fur; Ben\u2019s pet barks. Who has the bird?
Show worked solution
Ben = dog. Ana can't have fur (dog/cat) → Ana has the bird; Cara the cat.
3 List all 2-digit numbers from digits 5 and 6 (repeats allowed). How many are there?
Show worked solution
55, 56, 65, 66 → 4.
Level 2 · Core
4 I am a 2-digit number. My tens digit is double my ones digit. My digits add to 9. Who am I?
Show worked solution
Tens = 2 × ones; sum 9 → 6 and 3 → 63.
5 Counters 1-9 in a bag. How many are even?
Show worked solution
2, 4, 6, 8 → 4 (odds win 5-4 in 1-9!).
6 From digits 2, 3, 7 (no repeats): how many 2-digit numbers can you make?
Show worked solution
23, 27, 32, 37, 72, 73 → 6.
Level 3 · Challenge
7 Numbers 1-5 in a cross, lines add to 9 each. What is the middle number?
Show worked solution
Lines total 18, numbers 15 → middle = 18 − 15 = 3.
8 Counters 1-11: how many are GREATER than 6?
Show worked solution
7, 8, 9, 10, 11 → 5 (same as 1-5: five each — that is the OC trap!).
9 Three friends finish a race. In how many different orders can they finish?
Show worked solution
Robot list with A first: ABC, ACB; B first: BAC, BCA; C first: CAB, CBA → 6.