# Fraction Calculator: Add and Subtract Fractions

## Basic definition of a fraction

In mathematical terms, a fraction is a numerical quantity that is not a whole number: 1⁄3, 1⁄5, 2⁄7 etc.

A fraction is defined as a mathematical number that represents a part of whole number: 1⁄3, 1⁄6, 3⁄8 and so on. In everyday language we can simply say that a fraction how many parts of a certain size there are, like one eight-fifths.

## Simple methods of calculating Fractions

### Simple addition of fractions

The key thing to carrying out the addition of fractions correctly is to always keep in mind the most important part of the fraction is the number under the line, known as the denominator. If we have a situation where the denominators in the fractions involved in the addition process are the same, then we merely add the numbers that are above the separation line or as a mathematician would put it: "Adding the numerators only". We can have a look at an example of adding two fractions like 3⁄7 and 4⁄7. The expression would look like this: 3⁄7 + 4⁄7 = 7⁄7. In the case when the nominator is equal to the denominator, like in the foregoing example, it can also be equated to 1.

However, this was one of the easiest examples of adding fractions. The process may become slightly more difficult if we face a situation when the denominators of the fractions involved in the calculation are different. Nonetheless, there is a rule that allows us to carry out this type of calculations effectively. Remember the first thing: when adding the fractions, the denominators must always be the same, or, to put it in mathematicians language - the fractions should have a common denominator. In order to do that, we need to look at the denominator that we have. Here is an example: 2⁄3 + 3⁄5. So, we do not have a common denominator yet. Therefore, we use the multiplication table to find the number that is the product of the multiplication of 5 by 3. This is 15. So, the common denominator for this fraction will be 15. However, this is not the end. If we divide 15 by 3 we get 5. So, now we need to multiply the first fraction's numerator by 5 which gives us 10 (2 x 5). Also, we multiply the second fraction's denominator by 3 because 15⁄5 = 3. We get 9 (3 x 3 = 9). Now we can input all these numbers into the expression: 10⁄15 + 9⁄15 = 19⁄15

Note: When the nominator is greater than the denominator, we then divide it by the latter.

### Simple subtraction of fractions

The key thing to carrying out the subtraction of fractions correctly is to always keep in mind that the most important part of the fraction is the number under the line, known as the denominator. If we have a situation where the denominators in the fractions involved in the subtraction process are the same, then we merely add the numbers that are above the separation line or as a mathematician would put it: "Subtracting the numerators only". We can have a look at an example of subtracting two fractions like 3⁄7 and 4⁄7. The expression would look like this: 4⁄7 - 3⁄7 = 1⁄7.

However, this was one of the easiest examples of subtracting fractions. The process may become slightly more difficult if we face a situation when the denominators of the fractions involved in the calculation are different. Nonetheless, there is a rule that allows us to carry out this type of calculations effectively. Remember the first thing: when subtracting the fractions, the denominators must always be the same, or, to put it in mathematicians language - the fractions should have a common denominator. In order to do that, we need to look at the denominator that we have. Here is an example: 3⁄3 - 2⁄5. So, we do not have a common denominator yet. Therefore, we use the multiplication table to find the number that is the product of the multiplication of 5 by 3. This is 15. So, the common denominator for this fraction will be 15. However, this is not the end. If we divide 15 by 3 we get 5. So, now we need to multiply the first fraction's numerator by 5 which gives us 10 (2 x 5). Also, we multiply the second fraction's denominator by 3 because 15⁄5 = 3. We get 9 (3 x 3 = 9). Now we can input all these numbers into the expression: 9⁄15 - 10⁄15 = -1⁄15

Note: When the nominator is greater than the denominator, we then divide it by the latter.

You may also be interested in our Egyptian Fraction (EF) Calculator or/and Factoring Calculator