The Proof! tabletop card game is the inspiration behind our free, online Math Puzzle Challenges. Each carefully constructed puzzle consists of a set of nine cards that hides a challenging equation. This is a hand-picked selection of our trickier math puzzles that might involve some out-of-the-box thinking. If you would like, you can create an account to save your progress. Or if you already have an account, you can log in.

5.
Find a Triplet of 7's Using At Least 7 Cards
7.
Find Any Triplet of Fractions
9.
Find Any Pair Greater Than 50 Using Only Multiplication
13.
Find Any Pair Using All 9 Cards
14.
Find Any Quadruplet
15.
Find Any Triplet Less Than 0
17.
Find a Quadruplet of 1's
18.
Find Any Pair Using At Least 3 Square Roots
20.
Find a Pair of 2/3's
21.
Find 10 Different Quadruplets Less Than 10
23.
Find Any Quintuplet
29.
Find a Pair of 1000's
34.
Find a Pair of 667/1271's
35.
Find 7 Different Pairs Greater Than 15 Using Only Addition
36.
Find Any Pair Greater Than 0 Using All 9 Cards
39.
Find a Pair of 18's Using Only Subtraction
41.
Find a Pair of 10000's
42.
Find 5 Different Quintuplets Greater Than 0
43.
Find Any Pair Less Than 100 Using All 9 Cards and No Square Roots
47.
Find Any Pair Greater Than 0 Using All 9 Cards