Domino Arithmetic Games
Game 1
Imagine you have a bag of dominoes.
Draw one domino from the bag, and mentally compute the sum and product of the two numbers on it. (To find the sum, add the two numbers. To find the product, multiply the two numbers.)
Go again as long as you like.
This applet lets you choose the range of values on the dominoes, and it lets you check your answers. The answers of 0 are filled in by default--usually, you need to change them to the right answer.
Game 2
Play Game 1 first.
Now suppose your friend draws a domino and tells you the sum and product of the two numbers on it.
Can you figure out what the two numbers must be?