It all adds up

Here's an example of adding fractions. Follow the steps below to add the fractions and .

1. Find the lowest common denominator. Because the denominators in and are both prime numbers, multiply 7 by 3 to find the lowest common denominator, 21.

2. Then convert the fractions by multiplying each by 1 (in the form of a fraction) to yield fractions with the lowest common denominator.

3. Start by converting to :

   

4. Then convert to

   

5. Now, add the new fractions. To add fractions with a common denominator, add the numerators and place the result over the common denominator. The resulting fraction is your answer. (Reduce it to its lowest terms, if possible.)

   

Additional addition

To add and , follow these steps:

1. Find the lowest common denominator. In this case, because the denominators 2 and 5 are both prime numbers, multiply 2 by 5 to find the lowest common denominator, 10.

2. Convert the fractions by multiplying each by 1 (in the form of a fraction) to yield fractions with the lowest common denominator.

3. Convert the fraction to :

   

4. Then convert to :

   

5. Now, add the converted fractions. To do this, add the numerators and place the result over the common denominator:

   

Another additional addition

To add and , follow these steps:

1. Find the lowest common denominator—in this case, 15.

2. Convert the fractions by multiplying each by 1 (in the form of a fraction) to yield fractions with the lowest common denominator.

3. Convert to to :

   

4. Then convert to :

   

5. To add the converted fractions, add the new numerators and place the result over the common denominator:

   

6. Reduce the fraction to its lowest terms: