Treat the blank as a small calculation issue, not a crisis. Pause, break the multiplication into easier pieces, and keep your explanation calm.

For 7 x 8, you might use 7 x 4 x 2. For 12 x 6, use 10 x 6 plus 2 x 6. The decomposition matters more than proving you can recall every fact instantly.

If you still cannot recover, write the calculation and work it through rather than guessing. A correct, transparent method is better than a confident wrong number.

Practice basic arithmetic under mild time pressure so these recovery methods become automatic. The goal is resilience, not perfect recall. After recovering, move on without apologizing repeatedly; dwelling on the slip creates more disruption than the arithmetic mistake itself. For more detail, see the case interview mental math guide.