Adding and Subtracting Fractions with Unlike Denominators

Subtraction of denominators

A common denominator

A common numerator

Equivalent numerators

To find the common denominator

To multiply the fractions

To simplify the fraction

To divide the fractions

Add the two numbers

Find the first common multiple when skip counting

Multiply the two numbers

Subtract one number from the other

It is multiplied by the same factor

It is subtracted by the same factor

It is divided by the same factor

It remains the same

Find the LCM again

Simplify the fraction

Add the numerators

Multiply the fractions

1 7/12

2/12

1 5/12

5/12

2/20

7/20

2/5

3/10

9

3

18

27

Converting back to the original fractions

Finding a new LCM

Adding or subtracting the numerators

Multiplying the denominators

To improve multiplication skills

To understand fractions better

To be able to simplify fractions

All of the above