Hands-on math!

Algebraic expression

An algebraic expression is a mathematical phrase that can contain ordinary numbers, variables (like x or y) and operators (like add,subtract,multiply, and divide).
Here are some algebraic expressions:
a + 1

a - b


x - a / b

In the above expression the "/" means divide. The "3x" means multiply the variable x by 3.

Many english phrases translate directly into algebraic expressions, as shown in the following table (where x stands for "a number"):

English expression Algebraic expression
A number plus eight x + 8
four less than a number x - 4
half of a number x / 2

If you set an algebraic expression equal to something, with an equal sign, you now have an equation, like:
X - 4 = 10
To learn more about expressions, see the notes on variables, operators and expressions

So, here are a couple of problems for you (use x as your number):
  1. The expression for "3 times 8 less than a number" = ________________ <== (this needs parentheses)

  2. The expression for "8 divided by 3 times a number" = __________