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. If you would like, you can create an account to save your progress. Or if you already have an account, you can log in.

21.
Find 10 Different Quadruplets Less Than 10
22.
Find Any Pair Using Multiplication At Least 3 Times
23.
Find Any Quintuplet
24.
Find Any Pair Greater Than 0 Using Exactly 8 Cards
25.
Find a Pair of 44's
26.
Find 6 Different Pairs Less Than 20 Using Exactly 3 Cards each
27.
Find Any Triplet Using At Least 5 Square Roots and No Addition or Subtraction
28.
Find Any Triplet Greater Than 100
29.
Find a Pair of 1000's
30.
Find Any Pair Greater Than 0 Using All 9 Cards
31.
Find Any Pair Using Division At Least 3 Times
32.
Find Two Different Triplets
33.
Find a Pair of 27'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
37.
Find a Triplet of 8/9's
38.
Find 14 Different Pairs Greater Than 0 Using Exactly 3 Cards Each
39.
Find a Pair of 18's Using Only Subtraction
40.
Find 6 Different Pairs Less Than 0 Using Exactly 4 Cards Each