Positive and Negative Numbers – What Numbers Mean

We use numbers to show how many or how much there is of something:

  • People have 2 eyes
  • There are 5 toes on a foot
  • There are 7 days in a week
  • There are 12 inches in a yard
  • You have 15 pennies in your pocket … and so on

We use positive numbers to show these things. Up until now we probably haven’t said “positive numbers” ; we’ve just said “numbers”.

We show positive numbers with a + sign
+5 means positive five
We usually don’t say “positive” even though that is what we mean so…
5 is the same as +5

Using Negative Numbers

  • The temperature is 12 degrees colder than yesterday
  • I owe my sister 6 dollars
  • My friend wants to lose 10 pounds
  • The car was driving 5 miles per hour under the speed limit

Negative numbers are less than zero

We need numbers to represent these things too. We use negative numbers.

We show negative numbers with a – sign
-7 means negative seven
Sometimes people say “minus seven” instead of “negative seven” – they both mean the same

Negative numbers let us show values without using lots of words. Negative numbers are useful for calculations.

Using WordsWith Negative Numbers
A golfer scored 70 on a par 72 course (two under par)Her score was -2
A man owed $500 to the bankHis balance was
-$500
The quarterback gets sacked and the team loses 15 yards.The team is -15 yards on the play
The temperature changed from 10 degrees above zero during the day to 10 below zero at nightThere was a -20 degree change in temperature

Negative numbers are less than zero

The number line below shows how negative numbers go to the left of zero.