Definition of words
(1) [specific value; ratio ]: the value obtained by comparing two numbers Column: The ratio of 8 to 2 is 4
(2) [ratio]: the quotient of one quantity divided by another quantity. Also called ratio.
(3) In epidemiology, ratio (odds) refers to the ratio of the possibility of something happening to the possibility of not happening. [1]
※ a b Two quantities of the same kind, division can also be called comparison.
The dividend a is more than the preceding term consequent Divider b. The division sign is equivalent to the comparison sign. The quotient of division is called the ratio.
Non zero numbers can be compared with fractions.
The denominator is the second term of the ratio, and the first term of the ratio is the numerator.
The division quotient component value is also a ratio.
Don't forget to use the same unit to calculate the ratio between two similar quantities.
The ratio is a number, and the result cannot be a point ratio.
When the preceding and following terms of the ratio are multiplied or divided by the same number (except 0), the ratio remains unchanged. This is called Basic properties of ratio 。 
