Mental Math

Controls Goal: solve as many additions, subtractions and multiplications as you can in 60 seconds. Controls: press Start to run the clock and get the first problem. As soon as you have typed enough digits for the answer it is checked, so you do not need Enter (phones show a number pad). If you cannot do one, press Skip (or Enter in the box). Rules: a wrong answer empties and shakes the box with no penalty. After 8 and 20 correct answers the numbers get bigger (one/two digits, then two digits, then three-digit sums and bigger products). A subtraction never has a negative answer. Scoring: the number of correct answers in 60 seconds, higher ranks higher. There is no pause. The bar on top is the time left and turns red in the last 10 seconds. Tips: skip anything that takes long. For products use the times table and tens first; for two-digit sums add tens and ones separately. Right answers in a row raise the sound a step each.