(A) the law of quotient invariance

Law of quotient invariance: in division, the dividend and divisor expand or shrink by the same multiple at the same time, and the quotient remains unchanged.

(B) the nature of decimals

The nature of decimals: add or remove zero at the end of decimals, and the size of decimals remains unchanged.

(3) The movement of decimal position causes the change of decimal size.

1. If the decimal point moves one place to the right, the original number will be expanded by 10 times; If the decimal point is moved two places to the right, the original number will be expanded by 100 times; If the decimal point is moved three places to the right, the original number will be enlarged by 1000 times.

2. If the decimal point moves one place to the left, the original number will be reduced by 10 times; If the decimal point is moved two places to the left, the original number will be reduced by 100 times; If the decimal point is moved three places to the left, the original number will be reduced by 1000 times.

3. When the decimal point moves to the left or right, you should use? 0 "complement bit.

(D) the basic nature of the score

The basic nature of a fraction: both the numerator and denominator of the fraction are multiplied or divided by the same number (except zero), and the size of the fraction remains unchanged.

(5) the relationship between fraction and division

1. Dividend? Frequency divider = frequency divider/frequency divider

2. Because zero can't be divisible, the denominator of the fraction can't be zero.

3. Divider is equivalent to numerator and divisor is equivalent to denominator.

Knowledge points of mathematics in Xiaoshengchu: introduction of fractional calculation skills