What are the three mantras for fractions to size?

The mantra for fractions to size is as follows:The molecule is the same for two fractionsDenominatorThe fraction with the smaller denominator is larger, the fraction with the larger denominator is smaller, and the fraction with the same denominator is larger and the fraction with the smaller numerator is smaller. Divide an object or a figure into several parts, and take a few of them, which is the fraction of the object or figure.

The greater the number of shares an average of a whole, the smaller the number of copies represented by each one.

1. In the case of the same numerator, the smaller the denominator, the larger the score.

For example, 1 2> 1 3.

2. When the denominator is the same, the larger the numerator, the larger the score.

For example, 2 3> 1 3.

Fraction comparison size method1. General division method.

Change the denominator to the same through the denominator;

Turn the molecule into the same molecule.

2. Cross-multiplication.

The numerator does not move, and the denominator crosses and multiplies and moves over. Compare the product size that is the fraction size.

3. Doubling method.

If it's not close to 1, but close to a certain fraction, such as 4 13 and 6 19 are close to a third, then multiply them by 3 to make them close to 1. Multiplying or dividing by a number (except 0) does not affect the relationship between the magnitude of the two fractions. Change to 12 13, 18 19, and then compare using the benchmark number method.

If the number of places in a finite decimal is a single digit, then the infinitesimal should be kept to two decimal places for better comparison, so it should be divided to the third decimal place and rounded to find the approximate number.

Fraction ratio to size mantra:

The numerator is the same as the two fractions, the denominator.

The fraction with a small denominator is larger, and the fraction with a larger denominator is smaller; For two fractions with the same denominator, the fraction with the larger numerator is larger and the fraction with the smaller numerator is smaller.

1 Fraction Definition, a fraction represents a part of a whole, or more generally, any part of an equal number, a fraction describes a part of a certain size, such as half, five-eighth, three-quarter. Numerators and denominators are also used for uncommon fractions, including compound fractions, complex fractions, and mixed numbers.

Nature of Fractions:

1. A fraction is either a finite decimal or an infinite cyclic decimal, and an infinite non-cyclic decimal like .

It is impossible to replace it with a fraction.

2. When the numerator and the denominator are multiplied or divided by the same number at the same time (except 0), the fractional value will not change. Therefore, for each score there is an infinite number of equal scores. Taking advantage of this property, it is possible to divide and divide.

3. The denominator must not be 0, because the denominator is equivalent to the divisor. Otherwise, the equation cannot be held and the numerator can be equal to 0 because the numerator is equivalent to the dividend.

It is equivalent to 0 divided by any number, regardless of the denominator, the answer is 0.

1. For two fractions with the same numerator, the fraction with a smaller denominator is larger, and the fraction with a larger denominator is smaller.

2. The denominator is the same as the two fractions, the fraction with a large numerator is relatively large, and the fraction with a small molecule is relatively small.

How to compare the size of the fractions:

1. "Convert to the same denominator" method: first convert two fractions with different denominators into two fractions with the same denominator, and then compare them according to "two fractions with the same denominator, and the fraction with a larger numerator is larger".

2. "Turning into the same molecule" method: first turn two fractions with different molecules into two fractions with the same molecule, and then compare them according to "two fractions with the same molecule, and the fraction with a small denominator is relatively large".

3. "Compare the reciprocal" method: Compare the size of two fractions by comparing the size of the reciprocal of two fractions. The lower reciprocal fraction, the larger original fraction; The larger the reciprocal fraction, the smaller the original fraction.

4. "Division" method: divide the first fraction by the second fraction, if the quotient is less than 1, the first fraction is small; If the quotient is greater than 1, the first fraction is larger; If the quotient is equal to 1, then the two fractions are equal.

5. "Reduction" method: Before comparing two fractions, divide the two fractional ridge imitation numbers, and then compare the size of the two fractions.