# Subtraction

## Uses Of Subtraction

The most familiar meaning for subtraction is called "take away." To find the answer if you take 5 eggs from a dozen, you subtract: 12 - 5 = 7.

Subtraction is also used to compare two numbers. When one wants to know how much colder -7.3° is than 13.8°, one computes the difference -7.3 - 13.8 to get -21.1°.

A third use of subtraction is to figure out a missing addend. If one has a certain sum of money, say $45.20 and wants to buy an article costing $85.50, subtraction is used to compute that needed amount: 85.50 - 45.20.

J. Paul Moulton

## Additional topics

Science EncyclopediaScience & Philosophy: *Stomium* to *Swifts*Subtraction - The Definitions Of Subtraction, Terminology, Properties, Uses Of Subtraction