Below Zero: Snowflake Hill

It’s a snowy winter day on Snowflake Hill, and Grandma Bea’s big thermometer hangs by her cabin door. When the weather gets colder than zero degrees, the red line drops below zero, and we need a new kind of number to say how cold it is: a negative number.

Remember: 0°C (zero degrees Celsius) is the temperature where water freezes into ice. Numbers below zero are negative numbers. They are written with a little dash in front: −4 is said “negative four” (some people say “minus four”). Numbers above zero are positive numbers: +4 and 4 are the same number. Zero itself is neither positive nor negative.

Magic trick: The little dash is like a shovel: it tells you the number is buried below zero, down under the snow.