Add up the alphabet
Give the different letters of the alphabet the numerical values 1–26 (A=1, B=2, etc.). Try to think of words in which the sum of the letters is 40 (or 45, 50 etc). Only math geeks can figure out this crazy numbers riddle. Can you?
Study the phone bill
Take a look at your phone bill and try to recall to whom each phone call was made. If you rely on your cell-phone full-time now, look back at your recent call log and try to remember what you and the other person spoke about.