45 x 20 / 5 = ?

Explanation

Elementary arithmetic includes the operations of addition, subtraction, multiplication, and division. It starts with the natural numbers and the written digits which represent them. The process for combining a pair of these numbers with the four basic operations traditionally relies on memorized results for small values of numbers, including the contents of a multiplication table to assist with multiplication and division. Elementary arithmetic also includes fractions and negative numbers, which can be represented on a number line.