The nine types of exception problems used and mean accuracy and latency for correct answers, as well as number of correct trials contributing to the analysis of the fMRI data.

Example feedback given for each problem:

4$-3 = X: 4$-3 = 4+5+6 = 15 (or 5+6+7 if participant had chosen that solution).

−2$4 = X: −2$4 = −2+−3+−4+−5 = −14.

208$3 = X: 208$3 = 208+207+206 = 621.

5$X = 12: 5$3 = 5+4+3 = 12.

X$4 = 30: 9$4 = 9+8+7+6 = 30.

X$X = 15: 5$5 = 5+4+3+2+1 = 15.

110$X = 434: 110$4 = 110+109+108+107 = 434.

5$2⅓ = X: 5$2⅓ = 5+4+⅓(3) = 10.

200$401 = X: 200$401 = 200+199+…−199+−200 = 0.