## Variable

Today on Math Out Loud we’ll focus on the word variable, v-a-r-i-a-b-l-e. When we first learned about letters when we were young, they were used for reading, writing and spelling. Now that we are older we know that letters can be used in math, too! A variable is aletter in a mathematical expression such as n, x, s, b, or any other letter. The variables are the letters. Numbers are not variables. A variable is a letter that represents aquantity that can change. In an algebraic equation such as x + 3 = 8, the variable is x. The numbers 3 and 8 in that equation are not variables. They are called constants. We’re the Math Masters with the word story of variables on Math Out Loud.

November 13th, 2008 at 7:00 pm

Your definition of “variable” is well done! Very often, mathematicians take a word or a symbol that already has a meaning and give it a new meaning just for mathematics. For example, the word degrees is a unit of measure for temperature, but mathematicians use the word degree to also describe the size of an angle. This can be very confusing to people trying to learn mathematics. You have acknowledged the first use of letters for most people (reading, writing, and spelling) and helped your readers move on to an additional, new usage for letters.

Thank you for helping to define mathematical terms in a way that many people who aren’t mathematicians will understand.

:>dr.theresa

University of Maine at Farmington

Farmington, Maine, USA