| ODDNUMBER | Not even considered mathematically (3-6) |
| ODDNUMBERS | They're not even considered mathematically (3,7) |
| UNDREAMT | Defile under a mountain was not even considered (8) |
| UNTHINKABLE | Blunt? Hankie was not even considered (11) |
| CALCULATE | Work out mathematically (9) |
| FIVEXFIVE | One way to 25, mathematically |
| OPERATION | Surgery, and mathematically what starts the answer to each asterisked clue (9) |
| IRRATIONAL | Mathematically, like two pieces of pie? Not sensible (10) |
| INIT | Not mathematically eliminated |
| EQUALS | Ed Sheeran's upcoming mathematically-titled album (6) |
| KLEINBOTTLE | A closed surface with one side, mathematically constructed (5,6) |
| TEN | "Perfect" number that's not mathematically perfect |
| PROVEN | Mathematically validated (6) |
| RECKON | Suppose you'll work it out mathematically (6) |
| NULLSET | Group without members, mathematically (4,3) |
| AMPERE | A base SI unit named after the formulator of an electromagnetism law that mathematically describes the magnetic force between two electrical currents (6) |
| AHEADFORFIGURES | Mathematically minded in advance, claiming a sum in the thousands (1,4,3,7) |
| EQUALTOONE | A match of two halves is mathematically all the same as a whole (5,2,3) |
| THETAS | Angles' representations, mathematically |
| TORI | Bagels, mathematically |
