Can You Count to Twenty?

Try to beat the clock by answering these randomly-generated addition problems in your head.

It's kind of like the countries of the world quiz, except the map is empty to start, and we don't list the countries you have already guessed.

Guess what each group of three things has in common. As you guess each answer correctly, it will be drawn in to create a work of art.

Click the countries whose flags are have EXACTLY two colors.