mind map
The nature of the ratio is 1. The product of the inner term is equal to the product of the outer term, if a/b=c/d and ad=bc.
2. the ratio property, if a/b=c/d, then (a+b)/b = (c+d)/d.
3. Fractional property, if a/b=c/d, then (a-b)/b = (c-d)/d.
The numerator and denominator of a fraction are multiplied or divided by the same number (except 0) at the same time, and the size of the fraction remains unchanged. This is called the basic nature of fractions. The basic nature of fraction is the theoretical basis of reduction and general fraction.
The above is my sixth grade math knowledge, I hope it will help you.