Big Numbers Below Zero: The Funfair

At the Funfair, Coach Nora runs the Wobble Toss: land a ring on a bottle to win points, wobble off and lose them! Scores can drop below zero, so the scoreboard needs negative numbers, and some of them are big.

Remember: When you take away a bigger number from a smaller one, the answer is negative, even with big numbers. 1. Check: is the number you take away bigger? Then the answer will be below zero. 2. Swap the numbers and subtract the usual way, big minus small. 3. Put a minus sign in front. For 2,345 − 3,000: 3,000 − 2,345 = 655, so 2,345 − 3,000 = −655.

Magic trick: Check first, then subtract. If the second number is bigger, write the minus sign before you start, so you can’t forget it!