1, fractional multiplication: the meaning of fractional multiplication is the same as integer multiplication, and it is a simple operation to find the sum of several identical addends.

2. Calculation rules of fractional multiplication: fractional multiplication by integer, the product of fractional numerator and integer multiplication is numerator, and the denominator remains unchanged; Fractions are multiplied by fractions, the product of numerator multiplication is numerator, and the product of denominator multiplication is denominator. But the numerator denominator cannot be zero.

3. Significance of fractional multiplication: The significance of fractional multiplication of integers is the same as that of integer multiplication, and both are simple operations for finding the sum of several identical addends. Multiplying a number by a fraction can be regarded as finding a fraction of this number.

4. Fraction multiplied by integer: the combination of numbers and shapes, converted into 5. Reciprocal: Two numbers whose product is 1 are called reciprocal.

Second, the percentage

1, definition: percentage means that one number is the percentage of another number. Percentages are also called percentages or percentages. Percentages are usually not written in the form of fractions, but expressed by adding a percent sign "%"after the original molecules. For example: 90%, 90%; 108.5%, 108.5% ... percentages are widely used in industrial and agricultural production, science and technology and various experiments, especially in investigation, statistics, analysis and comparison.

2. The meaning of percentage: In production and life, we can describe the proportion of things in the whole more completely, thus saving a lot of unnecessary words, which is simple and appropriate.

Third, fractional division.

1, fractional division: fractional division is the inverse of fractional multiplication.

2. Calculation rule of fractional division: A divided by B (except 0) equals the reciprocal of A multiplied by B..

Fourth, the proportion.

1. In proportion, the product of two external terms is equal to the product of two internal terms. The nature of the ratio is used for the solution ratio.

2. The meaning of ratio is the division of two numbers, which is also called the ratio of two numbers, while the meaning of ratio is that the formula that indicates that two ratios are equal is called ratio. The ratio is the division of two numbers, and there are two items; Proportion is an equation, which means that two proportions are equal and there are four terms. So the meanings of ratio and proportion are different.

Verb (abbreviation of verb) quantitative relationship

1 copy × copy = total.

Total amount1number of copies = number of copies.

Total ÷ another copy = another number per copy.