A symbol (+ or –) that indicates whether a quantity is positive or negative.
In math, a sign tells us whether a number is positive or negative: The plus sign (+) means a number is positive, and the minus sign (–) means a number is… you guessed it: negative!
What do "positive" and "negative" mean?
It means above or below zero. For example:
- +7 means 7 units above zero.
- –3 means 3 units below zero.
We usually don’t write the plus sign in front of positive numbers because we use them daily, so it's understood that "5" means "+5." But we always write the minus sign for negative numbers.
Students sometimes confuse signs and symbols. In math, a sign tells us whether a number is positive or negative, while a symbol can represent many different things, like operations (×, ÷), relationships (=, >), or square roots (√). Signs are a special kind of symbol, but not all symbols are signs.
When Do Students Learn About Signs?
Students begin learning about positive and negative numbers and their signs in the upper elementary grades.
Grades 4–5 – Introduction to Positive and Negative Numbers
Students explore number lines, comparing numbers above and below zero, and begin understanding the use of signs.
Grades 6+ – Working with Signed Numbers
Students use signs in operations like addition and subtraction, and apply them in contexts like temperature, elevation, and money.
