1, ratio: The division of two numbers is also called the ratio of two numbers. The division relation of two numbers expressed by ratio.

2. Structure of ratio: In the ratio of two numbers, the number before the ratio sign is called the former item of the ratio, and the number after the ratio sign is called the latter item of the ratio.

The quotient obtained by dividing the former term by the latter term is called the ratio. The ratio is usually expressed in fractions, and can also be expressed in decimals or integers.

The simplest ratio: the first and last terms of the ratio are integers with only one common factor 1. This ratio is called the simplest integer ratio.

3. The ratio can represent the multiple relationship between two similar quantities: for example, the aspect ratio of a rectangle is15:10;

You can also express the division relationship between two different quantities and get a new quantity: for example, distance-time = speed.

4. Find the ratio:

The quotient obtained by dividing the former term by the latter term is called the ratio, so the latter term can be divided by the former term to obtain the ratio.

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

Whether the ratio has a unit: the ratio of the same quantity only indicates the multiple relationship between quantities, and its ratio has no unit;

The ratio of different kinds of quantities is a new quantity, usually using a compound unit (such as speed).

5. Relationship between ratio and ratio: both of them may be written in the same way (both can be expressed by fractions), but ratio represents the division relationship of two quantities; The proportion is a specific number.

6. Relationship among ratio, division and score: a:b=a÷b=a/b(b≠0)

The difference between ratio, division and score;

(1), with different meanings: the ratio indicates the division relation of two quantities; Division is an operation; The score is a number;

(2) Different expressions: division is an operation and can only be expressed by one expression; Both ratio and fraction can be expressed in the form of fractions, but fractions do not necessarily represent the ratio of two quantities.

(3) Different results: the result of division is quotient, which can be integer, decimal or fraction; Only when the ratio is needed, it needs to be calculated by division, and the ratio can be expressed by integer, decimal or fraction; And the score is a number and does not need to be calculated.

7. Why can't the last term of the ratio be 0: In division, the divisor can't be 0; The denominator in the score cannot be 0; The latter term of the ratio is equivalent to the divisor in division and the denominator in fraction, so the latter term of the ratio cannot be 0.

8. Unknown items in comparison:

(1), in division, dividend ÷ divisor = quotient, so long as you know any two of these three quantities, you can find the other quantity. Divider = Divider; Dividend = quotient × divisor.

② Ratio and division are essentially the same, that is to say, any two quantities can find another quantity in the ratio of the former, the latter and the ratio. The former = the latter × ratio; The latter item = the ratio of the previous paragraph; Ratio = first item, second item.

9. What's the difference between scores in sports competitions and scores in mathematics?

(1), the ratio in sports competition only indicates the score of both sides, such as 3: 2 or 1 1: 9, etc. , or 2: 0 or 0: 3.