Brain Exerciser Calculator keeps adult minds active with a simple but challenging math drill. Easily choose the number of math drill problems in increments of 25, 50 or 100. The Brain Exerciser calculates your score based upon speed and accuracy of responses. Top three scores are stored in the calculator's memory. Brain Exerciser also provides standard calculator functions with three-key memory, tax keys for easy tax calculations, percent, sign change, and right shift key for easy corrections. Calculator offers a 10 digit slant display with punctuation and runs on solar and battery power.