Numbers Below Zero

Integers are the whole numbers stretching in both directions from zero: ...−3, −2, −1, 0, 1, 2, 3...

The negative side was the troublemaker. How can you have fewer than nothing? But you already live with it. A bank overdraft is a negative balance. A freezer sits below 0°. Death Valley rests below sea level.

On a number line, integers march left for negative and right for positive. The further left, the smaller the value — so −10 is less than −3, even though 10 looks like the bigger number. That single flip trips up almost everyone at first.