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. The meaning of fractional multiplication The meaning of fractional multiplication by integers is the same as that of integer multiplication, which is a simple operation to find 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: combination of numbers and shapes, and conversion.

5. Reciprocal: Two numbers whose product is 1 are called reciprocal.

6. Find the reciprocal of a fraction, for example, 3/4 exchanges the numerator and denominator of 3/4 fraction, the original numerator is the denominator, and the original denominator is the numerator. It's four-thirds. 3/4 is the reciprocal of 4/3, or 4/3 is the reciprocal of 3/4.

7. Find the reciprocal of an integer, such as 12, divide 12 into several components, namely 12/ 1, and then exchange the numerator and denominator of the fraction of 12/ 1. The original numerator is the denominator. Is112,12 is the reciprocal of112.

8. Reciprocal of decimals: Common algorithm: Find the reciprocal of a decimal, such as 0.25, divide 0.25 into several components, namely 1/4, and then exchange the numerator and denominator of the fraction of 1/4, using the original numerator as the denominator and the original denominator as the numerator.

9. Calculate by 1: You can also divide this number by 1, for example, 0.25, 1/0.25 equals 4, then the reciprocal of 0.25 is 4, because the product is the reciprocal of 1. Fractions and integers also use this law.

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

Expanding knowledge: mathematics

Mathematics [English: Mathematics, from ancient Greece μ? θξμα(máthēma)； Often abbreviated as math or maths], it is a discipline that studies concepts such as quantity, structure, change, space and information.

Mathematics is a universal means for human beings to strictly describe and deduce the abstract structure and mode of things, and can be applied to any problem in the real world. All mathematical objects are artificially defined in essence. In this sense, mathematics belongs to formal science, not natural science. Different mathematicians and philosophers have a series of views on the exact scope and definition of mathematics.