The division of two numbers is also called the ratio of these two numbers. For example, a rectangle has a length of 6, a width of 4, an aspect ratio of 6 to 4, and an aspect ratio of 4 to 6.

6÷4 Write 6:4 in the form of ratio. ":"is a comparative symbol, pronounced "than". The number before the comparison symbol is called the first item of comparison, and the number after the comparison symbol is called the last item of comparison. In this example, 6 is the first term of this ratio and 4 is the last term of this ratio.

Compared with division and fraction, the former term of ratio is equivalent to divisor and numerator, the latter term is equivalent to divisor and denominator, the ratio is equivalent to quotient and fraction, and the sign of ratio is equivalent to divisor and fraction. Because the divisor and denominator cannot be "0", the latter term of the ratio cannot be "0". If the relationship among ratio, division and fraction is expressed by letters, it can be expressed as a:b=a÷b=a/b(b≠0).

Basic properties of ratio

(1) The two items before and after the ratio are simultaneously expanded or reduced by the same multiple (except 0), and the ratio remains unchanged.

(2) The former and the latter terms of the simplest ratio are reciprocal.

③ Ratio is usually expressed by ratio (horizontal form) or fraction (fractional form).

④ The latter term of the ratio cannot be 0.