What is a mathematical expression ? Definition and examples.

A mathematical expression, also called expression, is a mathematical sentence that includes at least one operation, numbers, and/or variables without an equal sign.

Examples of mathematical expressions

If one TV costs 400 dollars, how can the cost of buying 3 TVs at the same price be expressed?

3  × 400 is the mathematical expression for the cost of 3 TVs.

Suppose n represents the number of TVs you can buy at the same price of 400 dollars. How can the cost of buying n TVs be expressed?

n × 400 is the expression for the cost of buying n TVs.

An expression for 3 plus a number is 3 + x

An expression for the product of 6 and a number could be 6n, 6x, 6y, etc...

An expression for buying two books costing eight dollars each with a discount of three dollars is

2 × 8 - 3