How to calculate the addition and subtraction method with the same numerator and different denominat

The method of addition and subtraction with different denominators of the same numerator is:

The difference in the denominator of the fraction is the addition and subtraction of the fraction of the different denominator, and the first thing to pass is to pass the score.

Replace them with the same denominator fraction plus or minus, the denominator remains the same, the numerator is added and subtracted, and the lowest common multiple of the two denominators should be used when passing the score.

be their common denominator.

An example of an addition and subtraction method with the same denominator and different denominator is:

1.For example, 3 out of 8

Plus. 3/4, the denominator of the two numbers is 8 and 4 respectively, and the least common multiple of 8 and 4 is 8, then 3/4 is divided, that is, the numerator denominator is multiplied by 2 at the same time (the size of the fraction is unchanged) becomes 6/8, and then the addition operation is carried out.

3/8 plus.

3/38/4

Plus. 6 out of 8

91/8 and 1/8

2.If the result is a false score.

Generally, it should be reduced to a band fraction.

5/8 plus.

1/4 is similar, 1/4 is turned into 2/8, and then addition.

5/8 plus.

Plus 5/18/4.

28/8 7

Fractions (formulas) with the same denominator are added and subtracted].

When the denominator of two fractions (formulas) is the same, regardless of whether their numerators are the same or not, they add or subtract each other, and the denominator remains unchanged in the result, and the numerators are directly added or subtracted to obtain a new numerator;

Fractions of different denominators (formulas) are added and subtracted].

When the denominator of two fractions (formulas) is different, regardless of whether their numerators are the same or not, they must be divided before adding or subtracting, and then calculated according to the law of addition and subtraction of the same denominator;

According to the basic properties of fractions, the process of converting several fractions (formulas) with different denominators into fractions (formulas) with the same denominator equal to the original fractions (formulas) is called general fractions.

The method of passing points].

1. Find the common denominator. (The common denominator can be the least common multiple of two or more numbers.) ）

2. Then the denominator of two or more fractions that need to be divided is changed from a different denominator to the same denominator. According to the basic nature of fractions: the numerator and denominator of fractions are multiplied or divided by the same number at the same time (except zero), and the size of the fraction does not change.

Here's the key, after writing the same denominator, you have to see how many times the denominator is expanded compared to the original fraction, and then the numerator must also be expanded by how many times at the same time, so that the size of the score after the pass will be equal to the size of the original fraction. ）

The key to the score].

The key to the general division is to determine the simplest common denominator of several fractions, and the steps are as follows:

1.The divisor of each denominator is listed separately;

2.Multiply the divisor of each denominator, if there is a common divisor, multiply it only once, and the result is the least common multiple of each denominator;

3.All the factors that appear in the letter or the factor containing the letter as the base power are to be taken;

4.The factor of the power of the same letter or the factor containing the letter takes the exponent as the largest;

5.Multiply all the above formulas to get the simplest common denominator;

It is different from the same moleculeDenominatorThe addition and subtraction are: firstScoresThe different denominator fraction after the general fraction is calculated according to the law of addition and subtraction of the same denominator fraction, the denominator remains unchanged, the numerator is added and subtracted, and finally the fraction is reduced.

General Scoring Method:1. Find the least common multiple of the denominator of the original fractions.

2. According to the basic nature of the fraction, the original fraction is converted into a fraction with this least common multiple as the denominator.

Example: Calculate 5 6 + 7 8.

The least common multiple of 6 and 8 is 24.

24 is 4 times larger than 6, i.e. 5 6 = 20 24.

24 is 3 times larger than 8, i.e. 7 8 = 21 24.

So, 20 24 + 21 24 = 41 24.

The concept of heterodenominator fractions: it is two or more fractions with different denominators, which are called heterodenominators and have nothing to do with the numerator.

For example, for example, 1 2, 1 3, and 3 4 have different denominators, so they are different denominator fractions.

The numerator is the same, and the denominator is different, and the addition and subtraction can be passed through the general division.

to determine the simplest common denominator.

Then the addition and subtraction between the molecules is carried out in the following steps:

1. List the divisors of each denominator in the formula;

2. Multiply the divisors of each denominator in the formula, if there is a common divisor.

Multiply it only once, and the result is the least common multiple of each denominator.

3. If the letter appears or the factor containing the letter.

The factor of the power of the base should be taken;

4. The factor of the power of the same letter or the power of the destruction of the letter takes the largest exponent;

5. Multiply all the above formulas to get the simplest common denominator.

Example of the process of simplification after molecular separation:

The addition and subtraction method of judging the same denominator of the same numerator can be determined by the general fraction to determine the simplest common denominator, and then the addition and subtraction between the numerators is carried out, and the steps are as follows: 1. List the divisors of each denominator in the formula respectively; 2. Multiply the divisor of each denominator in the formula, if there is a male mask approximate only once, the result is the least common multiple of each denominator; 3. If the letter appears or the factor containing the factor of the letter as the base power should be taken; 4. The factor of the power of the same letter or the factor containing the letter takes the exponent as the largest; 5. Multiply all the above formulas to get the simplest common denominator.

Fractions with the same numerator and different denominators can be added and subtracted without digging through the denominator scatter, and the following formula can be used for flushing and scattering:

a/b+a/c=a(b+c)/bc

a/b-a/c=a(c-b)/bc (c＞b)

Add: the same denominator, the denominator does not change, the numerator.

Add. For different denominators, find the lowest common multiple of the denominator.

Specialized, after the general division of the molecules belong to the addition.

Less: Same as above. Multiplication: Multiply the denominator by the denominator and the numerator by the numerator.

Divide: equal to the reciprocal of the multiplication, as above.

Fractions with the same denominator are added.

The fraction with the same denominator is added, the denominator remains unchanged, the numerator is added, and finally it is reduced to the simplest fraction.

Example 1: 2 9 + 5 9 = 2 + 5 9 = 7 9

Example 2: 1 8+3 8=1+3 8=4 8=1 2 The fractions of the different denominators are added.

The fractions with different denominators are added together, first through the scores, and then calculated according to the addition of the fractions with the same denominator, and finally the simplest fraction is converted.

Example 1: 3 4+5 7=21 28+20 28=21+20 28=41 28

Example 2: 5 24+1 8=5 24+3 24=5+3 24=8 24=1 3

The numerator of the fraction is the same, the denominator is different, this is the heterodenominator, when calculating the addition and subtraction, you must first pass the fraction, and turn the heteronominator fraction into the same denominator, in the calculation, such as one-third plus one-quarter.

Just look at it.

First of all, the general division (find the least common multiple of the two denominators, according to the multiple of the denominator and the least common multiple, after the denominator and the numerator are multiplied by the multiple at the same time, the denominator is the same, and the numerator is adding and subtracting).

First pass. Find the least common multiple of the two fractions. The multiple of the denominator by the least common multiple of the denominator. The denominator remains unchanged, and the numerators are added and subtracted.

For the addition and subtraction of fractions with different denominators, the denominator must be the same first, otherwise the addition and subtraction have nothing to do with whether the numerator is one.

Hello, this kind of affection.

In this case, a mathematical term is used called a common score.

In this case, you can only first use the denominator for the general division, convert it into the same denominator in addition and subtraction, the general fraction is to expand the numerator and the denominator at the same time by the same multiple, generally need to convert the two denominators into the least common multiple of these two numbers, so that you can directly want to add, no need to divide the Jane, I hope to help you, hope to adopt.

The first pass is to find the least common multiple of the two denominators first, so that the denominator is the same!

The denominator is not the same, you must first pass the minute and then add or subtract, to find the least common multiple of the two denominators.

For example, if a third is added to a quarter, the least common multiple of 3 and 4 is 12, and after the division becomes 4 12 + 3 12 7 12

It has nothing to do with the molecule.

First, the denominator is divided so that the denominator value is the same, then the numerator is added or subtracted, and finally the numerator and denominator are simplified.

Alternate denominators are added to each other.

First pass the score, strike into the same denominator, and then add up. The general method is to find out the least common multiple of the two denominators, and then use the basic properties of the fraction to expand the numerator and denominator of the two fractions at the same time, so that the denominator becomes the least common multiple of the two, and finally the denominator remains unchanged, as the denominator of the new fraction, and the numerator is added as the numerator of the new fraction.

The decimals of the two fractions are not the same, but the numerator du is 1How to add or subtract. Hello, the overall dao is to pass the score first, and then add or subtract after the same denominator.

If the numerator of the two fractions is 1 and the denominator is a prime number, then the product of the denominator is the common denominator, and the numerator is the sum of the two original prime numbers.

or the difference between two primitives.

Example 1 5 + 1 13

13/65+5/65……The product is the common denominator, and this step can be saved after the division, and the direct denominator is added to 13 + 5 to do the numerator of the sum).

Example 1 5 + 1 13

8/65……Multiply the common denominator, and then subtract the denominator by 13-5 to make the difference numerator.

This method is only suitable for addition and subtraction where the two denominators are prime and the numerator is 1.

First, the denominator is consistent by the least common multiple, and then the result is added and subtracted, and the result is simplified.

First, the denominator is divided so that the denominator value is the same, then the numerator is added or subtracted, and finally the numerator and denominator are simplified.

The denominator of the two fractions is not the same, but the numerator is one. How do I add or subtract?

First pass points, then add and subtract.

First the same denominator, the numerator is the addition and subtraction of the two denominators, and finally in the reduction of the denominator.

The denominator is multiplied, and the numerator is the sum of the two denominators,

The numerator is the same, the denominator is different, the addition and subtraction should be the same as the divide, that is, the least common divisor between the two denominators, and the numerator is the mutual addition and subtraction of the two denominators.

Don't overthink it. There isn't much way to do it. Just make it the same denominator.

Don't think about molecules. Not the same as the monograph. Or the rights are not the same.

There is no effect on the denominator. Don't try to take shortcuts. Even if you find a shortcut.

You won't necessarily use it either. People often find shortcuts. It doesn't have to be the shortest road.

The denominator and numerator do not affect each other. Don't think about the numerator when writing fraction addition and subtraction. Just consider the denominator...

In fact, this has nothing to do with whether the numerator is the same, since the denominator of the two fractions is not the same, then it is required to first carry out the general score, make the denominator of the two fractions the same, and then carry out the addition and subtraction operation, which is not difficult.

When encountering mixed operations with different numerators and denominators, it is usually necessary to reduce these fractions to sibling fractions before performing the calculations. Hydroponics.

For example, to calculate (2 3) +1 4), you first need to reduce 1 4 to 4 16, and then add the numerator and denominator of the two fractions to give 2 3 + 4 16 = 2 3 + 2 8 = 2 3 + 1 4 = 8 12 + 6 12 = 14 12. Finally, 14 12 can be reduced to 1 1 12.

If you encounter a division operation, you need to swap the divisor and the dividend and transform it into a multiplicative operation, for example, the calculation (1 4) 2 3) can be converted to (1 4) *3 2) =3 8

In addition, it is necessary to pay attention to the use of parentheses when performing mixed calculations, so as not to bury the wrong arithmetic.

1.First, the numerator and denominator are calculated separately, and the results are written down separately.

2.If the numerator and denominator have a common factor, the common factor can be extracted, and then the numerator and denominator are divided by the common factor, and finally the answer is obtained.

Pass the score first, make the denominator the same, calculate the multiplication and division first, then calculate the addition and subtraction, and the one with parentheses is counted in the parentheses first.

The numerator is an alien of 1.

The square of the addition and subtraction of the denominator fraction.

Method: The product of the denominator is used as the denominator of the result, and the sum of the denominator or the difference of the denominator is used as the numerator of the result, and the result is reduced to the simplest fraction.

If the numerator is the same and the denominator is different, the denominator cannot be calculated according to the same denominator. Because the molecules are the same, there are certain particularities.

For example, if the numerator is the same but the denominator is different, it can be set to the following sub-form.

m/a+m/b

m（1/a+1/b）

m（a+b）/ab

m（b+a）/ab

where m is the same numerator, and a and b are not the same denominator.

In the same way, the minus form is sometimes present.

m/a-m/b

m（1/a-1/b）

m（b-a）/ab

If the numerator is different, the calculation with the same denominator will add up the number of numerators as the total number of numerators, and the denominator will not change.

Answer: Hello, it's a pleasure for me to answer for you [Love you] The addition and subtraction of different denominator fractions and the addition and subtraction of fractions with the same denominator have the same meaning, but the calculation process is different; The fraction of the same denominator is added or subtracted, the denominator does not change as the denominator, and the result of addition and subtraction of the numerator is the numerator; The fractions of different denominators are added and subtracted, and the fractions of different denominators are divided first, and then calculated according to the addition and subtraction of fractions of the same denominator.

That is, the first score, in the calculation yo [love you].