1. Divide the unit "1" into several parts on average, and the number representing such a part or several points is called a fraction.

2. Divide the unit "1" into several parts, indicating the number of these parts, which means decimal unit. A score consists of several fractional units.

3. Scoring rate: divide the unit "1" into several shares on average, and find the scores of other quantities in the total shares.

Single quantity: total quantity ÷ quantity = single quantity (expressed in fractions)

(The denominator of a single quantity and score is the total number of average scores)

4. The relationship between fraction and divisor:

Frequency divider/frequency divider = frequency divider/frequency divider A/B = A/B (b ≠ 0)

5. Unit conversion: When changing the name of a low-level unit to the name of a high-level unit, if the number on the low-level unit is not divisible by the advancing rate, the quotient can be expressed by a fraction. (Result discount points)

6. Score comparison:

Two numbers with the same denominator, the number with the larger numerator is larger.

Two numbers with the same numerator, the number with the smaller denominator is larger.

7. Fractions with numerator less than denominator are called true fractions. Features: True score is less than 1.

Fractions with numerator greater than or equal to denominator are called false fractions. Features: False score is greater than 1 or equal to 1.

8. Method of turning a false score into an integer or a fraction: turn a false score into an integer or a fraction, and divide the numerator by the denominator. If it is divisible, the quotient is an integer. The numerator is divided by the denominator, the integer that cannot be divided is the quotient, the remainder is the numerator, and the denominator remains the same.

The method of changing a fraction into a false fraction: integer multiplied by denominator, numerator as denominator, denominator unchanged.

9. The basic nature of the score:

1. Both the numerator and denominator of the fraction are multiplied or divided by the same number (except 0), and the size of the fraction remains the same.

2. The denominator of the fraction remains the same, and the molecular magnification is several times, so is the size of the fraction. If the numerator remains the same, the denominator is enlarged several times, but the fraction is reduced by the same multiple.

10. Meaning of common factor and greatest common factor: The common factor of several numbers is called the common factor of these numbers. The greatest common factor of several numbers is called the greatest common factor of these numbers.