Numerical expressions are numbers and signs, like below. The following are some examples of numerical expressions, numerical expressions do not use letters.
4 + 20 – 7, (2 + 3) – 7, (6 × 2) ÷ 20, 5 ÷ (20 × 3)
An algebraic expression uses letters and it says you to find "x/y/z".
Example;
4+20xy-7x, (2x+3) - 7y+20.
