How to Add Fractions (and Multiply and Divide Fractions)
28th October, 2021
When I teach how to add and subtract fractions, I start with explanations of equivalent fractions and how to simplify them.
Moving on from that, I look at multiplying and dividing fractions – which is easier than adding and subtracting!
Table of Contents
Equivalent Fractions and Simplifying Fractions
If you multiply or divide the numerator and denominator by the same number you have an equivalent fraction.
“Whatever you do to the top, you do to the bottom”
If you can divide the top and bottom by the same number, you can simplify the fraction.
How to Multiply Fractions
Multiply Fractions – Multiply tops and bottoms
Multiply Fractions – Simplify Fraction
How to Divide Fractions
Divide Fractions – change to a multiply question
To divide fractions, we change it to a multiply question, using “K.F.C.” – Keep, Flip, Change.
- Keep the first fraction
- Flip the numbers on the second fraction
- Change the question to a multiplication
Divide Fractions – Multiply
Divide Fractions – Simplify Fraction
How to Add and Subtract Fractions
How to Add and Subtract Fractions – when the denominators are the same
The denominators remain the same, simply add or subtract the numerators to find the sum of the fractions.
How to Add and Subtract Fractions – when the denominators are different
Change to equivalent fractions with common denominators, then add or subtract.
And what’s the best common denominator to use? The one that is the lowest common multiple of the two denominators.
e.g. the lowest common multiple of 3 and 4 is 12. The lowest common multiple of 2 and 5 is 10.
Printable revision guides on How to Simplify Fractions, How to Add / Subtract Fractions, How to Multiply Fractions and How to Divide Fractions
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My name is Nicola Bhalerao and I am a private tutor based in Warwick. Since 2013, I have provided one-to-one tuition for children and adults. I specialise in maths tutoring, but cater for different requests, ranging from 11+ to various computing skills, including website training.
My background is in computing, with a Computer Science degree from Warwick University. I have worked many years as a programmer, latterly in the games industry. Both my sons were tutored by me for the 11+ (they went to a local grammar school). I received training for teaching secondary school maths and I am fully CRB checked.
I am a WordPress expert, having spent many years creating numerous websites with my other business, Smiling Panda Web Design. Although I no longer actively work on websites for others, I offer help with understanding / updating / creating your own WordPress website.