A modification of the Cognitive Estimation Test (CET) by Shallice and Evans was developed to assist in the scoring and interpretation of this measure of problem solving. Two studies were presented. In Study 1, the modified CET that required numeric responses was administered to 164 employed adults. Deviation scores were derived from percentiles from mean performance of this sample. Total deviation scores were highest for the least educated group. Study 2 found CET deviation scores to be significantly higher for a severe traumatic brain injury group relative to a sample of medical outpatients. The normative and clinical data presented are meant to serve as a starting point for further validation of this new measure.