Getting to grips with the 4 basic arithmetic operations (**Add / Subtract / Multiply / Divide **) when using fractions can easily be achieved once you know some basics rules:

With adding and subtracting, the rule is to make sure **the denominators are the same** before you can add or subtract fractions. if not, then multiply one (**Case II**) (or both fractions (**Case II**I) ) by a number so as to end up with fractions having the same number as the denominator.

**Case I**: Fractions have the same denominator. We simply add or subtract the numerator.

**Case I**I: Fractions have different denomintors. However, multiplying on of the fractions by a number (in this example by 2) we end up with both fractions having the same denominator.

**Case III**: This is the most complex example. In this case, we have to multiply both fractions by a number so as to obtain the same denominator in both fractions. The first fration is multiplied by 4 an d the second fraction by 7.

The full video lesson on adding and subtracting fractions is foundhere.