Math Bugs Me home

Sometimes you may not know all the numbers when writing out a math problem. You can use letters or symbols to represent the numbers. These letters and symbols are called variables.

Back in elementary school, you did the same thing but the variable was often represented by a box or square or even a cute little picture like this:

Now, we will be using letters. The letters, called variables, represent unknown letters and/or symbols.

The same examples presented above, when using a variable, would look like:

These two examples are called expressions (mathematical phrases). To be even more specific, they are variable expressions because they each contain variables. A variable expression contains variables and may even contain numbers.

Expressions can be described or explained using words.

For example, the first expression can be described as: "the sum of three and b"

The second expression could be described in words as: "six less than n"
Variable expressions are not the same as numerical or number expressions. A number expression has ONLY numbers.

Examples of numerical expressions: 5 + 6 24 – 9 12 • 5

A variable can be immediately preceeded by a number. If you see 9z then you have a coefficient and a variable. 9 is the coefficient and z is the variable. 9 is multiplied by the variable z.

+5 is the constant because its value doesn't change even if the value of the variable changes

9 is the coefficient and is multiplied by z

z is the variable

A term is a group of numbers and variables. So, how many terms do you see on this page altogether?

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