Put the unit? 1? Divide into several parts on average, and the number indicating this part or parts is called a score.

In the score, the middle horizontal line is called the dividing line; The number below the fractional line, called the denominator, represents the unit? 1? How many shares are divided equally; The number below the fractional line is called the numerator, indicating how many copies there are.

Put the unit? 1? Divide into several parts on average, and the number representing one part is called fractional unit.

2. How to read the spectrum: read the denominator before reading the spectrum? Share it? Then read the numerator, numerator and denominator as integers.

3. Writing of fractions: Write the fractions first, then the denominator, and finally the numerator, according to the whole number.

4, compare the size of the score:

(1) The fraction with the same denominator is the largest numerator.

(2) The scores with the same numerator are larger with smaller denominator.

(3) Fractions with different denominators and numerators are usually divided first, converted into fractions with a common denominator, and then compared.

(4) If the scores to be compared have scores, compare their integer parts first, and the score with the larger integer part is larger; If the integer parts are the same, then compare their decimal parts, and the decimal part with the largest decimal part is the largest.

5. Classification of scores

According to the different conditions of numerator, denominator and integer, it can be divided into true fraction, false fraction and band fraction.

(1) True fraction: The fraction with numerator less than denominator is called true fraction. The true score is less than 1.

⑵ False fraction: Fractions with numerator greater than denominator or numerator equal to denominator are called false fractions. False score is greater than or equal to 1.

⑶ Fractional: False fraction can be written as a number consisting of integer and true fraction, which is usually called fractional.

6. The relationship between fraction and division and the basic properties of fraction.

(1) division is an operation with operation symbols; The score is a number. Therefore, it should generally be said that dividends are equivalent to a molecule, but it cannot be said that dividends are a molecule.

(2) Because fractions are closely related to division, according to division? Business remains the same? The basic properties of fractions can be obtained from the properties of.

(3) The numerator and denominator of a fraction are multiplied or divided by the same number (except 0), and the size of the fraction remains unchanged. This is called the basic nature of fraction, which is the basis of divisor and total fraction.

7. Subtraction and total score

(1) A fraction whose numerator and denominator are prime numbers is called simplest fraction.

⑵ Changing a fraction into a fraction equal to it, but with smaller numerator and denominator, is called a reduced fraction.

(3) Reduction method: divide the denominator by the common divisor of the denominator (except 1); Usually, we have to separate it until we get the simplest score.

(4) Fractions of different denominators divided by scores of the same denominator are equal to the original score, which is called the total score.

5. General division method: first find the least common multiple of the original denominator, and then turn each fraction into a fraction with this least common multiple as the denominator.

8. countdown

(1) Two numbers whose product is 1 are reciprocal.

(2) To find the reciprocal of a number (except 0), just switch the numerator and denominator of this number.

(3) The reciprocal of 1 is1,and 0 has no reciprocal.