The computer will generate two random numbers for you to calculate. Each number has a maximum of two digits. The answer for each question is so easy that you can calculate the answer in your head without using a calculator. If the answer is two digits, it will display '??' and if the answer has a remainder, it will display the word 'remainder' with the correct value. For example, if you think the answer is 11 remainder 5, press or touch '1' button twice then press or touch 'OK' button.