Advice 1: How to solve fractions 5th grade

In the 5th grade middle school introduces the concept of fractions. A fraction is a number consisting of a whole number of share units. Fractions are written in the form ±m/n, the number m is called the numerator, the number n of its denominator.
If the module of the denominator is greater the numerator of the module, such as 3/4, the fraction is called proper, otherwise improper. A fraction may contain the integer part, for example 5 * (2/3).
To fractions, you can apply different arithmetic. Instruction
1
Bringing to a common denominator.

I suppose that fractions a/b and c/d.

- First and foremost is the number of knock(least common multiple) for the denominators of the fractions.

- The numerator and denominator of the first fraction is multiplied by the NOC/b

- The numerator and denominator of the second fraction is multiplied by the NOC/d

An example is shown in the figure.

To compare fractions, they must lead to a common denominator, then compare the numerators. For example, 3/4 < 4/5, see figure. 2
Addition and subtraction of fractions.

To find the sum of the two fractions need to be brought to a common denominator, then put the numerators, leaving the denominator unchanged. Example of addition of fractions 1/2 and 1/3 are shown in Fig.

The difference of the fractions is the same way, after finding a common denominator, the numerators of the fractions are subtracted, see the example in the figure. 3
Multiplication and division of fractions.

When multiplying fractions, the numerators and denominators are multiplied together.

In order to divide two fractions, you need to roll back the second fraction, i.e. to change its numerator and denominator reversed, and then multiplying the obtained fractions. Advice 2 : How to solve problems with fractions

To solve the problem with fractions, you need to learn how to do arithmetic. They can be decimal, but most often uses natural fraction with the numerator and denominator. Only after that you can go to to solve math problems with fractional quantities. You will need
• calculator;
• - knowledge of the properties of fractions;
• - the ability to perform operations with fractions.
Instruction
1
The roll call record of division of one number by another. Often to do this completely is impossible, therefore, leave this step "unfinished . A number that is divisible (it is above or in front of the sign of the fraction) is called the numerator and the second number (under the sign of the fraction or after it) is the denominator. If the numerator is more than denominator, the fraction is called improper, and it is possible to allocate the integer part. If the numerator less than the denominator, such a fraction is called proper, and its integer part equal to 0.
2
Tasks with fractions are divided into several types. Determine which of them is the challenge. The simplest option – finding fractions of numbers expressed in fraction. To solve this problem, it is sufficient to multiply this number by the fraction. For example, the warehouse delivered 8 tons of potatoes. In the first week, it sold 3/4 of its total. How many potatoes are left? To solve this problem, the number 8 and multiply by 3/4. Makes 8∙3/4=6 t
3
If you want to find the number of parts, multiply the known part of a number the inverse of that which shows what proportion of this part in the number. For example, 8 students constitute 1/3 of the total number of students. How many children are studying in class? Because 8 people is the part that is 1/3 of the total number, then find the inverse fraction, which is equal to 3/1 or just 3. Then, to obtain the number of students in class 8∙3=24 students.
4
When you need to find what part number is one number from another, divide the number which represents the part on that which is whole. For example, if the distance between the cities is 300 km and the car has driven 200 km, what part of this is from all the way? Share part of the journey 200 with the complete path 300, after the reduction of the fraction will get the result. 200/300=2/3.
5
To find the unknown part of the proportion of when there is known to take an integer for the standard unit, and subtract from it a certain amount. For example, if you have passed 4/7 part of the lesson, how long? Take the whole lesson as a conventional unit and subtract from it 4/7. Get 1-4/7=7/7-4/7=3/7.
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