Please agree to accept our cookies. If you continue to use the site, we'll assume you're happy to accept them. # 3.8 Common denomination: more adding and subtracting

Created on 21 August 2019 by ncetm_administrator
Updated on 22 August 2019 by ncetm_administrator

## Introduction

Learn to add and subtract fractions with different denominators by first finding a common denominator. Compare fractions using a range of methods, including converting to a common denominator.

## Teaching points

• Teaching point 1: In order to add related fractions, first convert one fraction so that both share the same denominator (a ‘common denominator’).

• Teaching point 2: To subtract related fractions, first convert one fraction so that both share a common denominator.

• Teaching point 3: The common denominator method can be extended to adding and subtracting non unit related fractions.

• Teaching point 4: To add and subtract non-related fractions, the product of the two denominators provides a common denominator.

• Teaching point 5: Converting to common denominators is one of several methods that can be used to compare fractions.   Add to your NCETM favourites Remove from your NCETM favourites Add a note on this item Recommend to a friend Comment on this item Send to printer Request a reminder of this item Cancel a reminder of this item