The meaning of 1. ratio: ratio is a division formula consisting of the former item and the latter item, that is, the division symbol is changed to the comparison symbol, but the division formula represents an operation, and the ratio represents the relationship between two numbers, which is similar to the fractional line of a fraction;

2. The basic nature of the ratio:

The two items before and after the ratio of 1. are multiplied or divided by the same number at the same time, and the ratio remains unchanged except 0;

2. The front and back terms of the simplest ratio are prime numbers, and the front and back terms of the ratio are integers;

3. The ratio is usually expressed as an integer, and can also be expressed as a fraction or decimal;

4. The last item of the ratio cannot be 0;

5. The latter term of the ratio is multiplied by the former term of the ratio equal to the ratio;

6. The former term of the ratio is equal to the latter term.