| DECIPHER | Solve a code |
| CRACK | Give way under stress, but was able to solve a code, etc (5) |
| CLUE | Derived from a word meaning "ball of thread", a hint or tip that helps to solve a mystery or a puzzle (4) |
| PASCAL | Inventor of a calculator whose correspondence with Pierre de Fermat to solve a gambling puzzle led to the pair's formulation of a theory of probability (6) |
| BLACKBOARD | Where a student may solve a problem |
| PEN | What a confident person might solve a crossword with |
| FORMULA | A set of symbols that are used to solve a problem (7) |
| PUTINAWORDORTWO | Intervene in conversation and solve a bit of a crossword? (3,2,1,4,2,3) |
| GOTOPIECES | How to solve a jigsaw? You may have a breakdown! (2,2,6) |
| AHA | Exclamation when you solve a tricky clue in a crossword puzzle |
| PASSTIME | Solve a crossword in a waiting room, say |
| CRACKTHECASE | Solve a mystery, and a hint to the answers to the starred clues |
| TYPE | Solve a crossword on a phone, for example |
| BIND | Unable to solve a dilemma (with "in a") |
| ALGORITHM | In mathematics, a set of instructions or rules that can be followed to solve a problem (9) |
| INPEN | Bold way to solve a crossword |
| FREE | Solve a difficult problem |
| CLEAR | Solve a difficult problem |
| RESOLVE | Solve a difficult problem |
| WORKOUT | Solve a difficult problem |
