How do I add fractions?

When adding fractions, the denominators(the numbers at the bottom of the fractions) must be the same. If they are already the same, then you simply add the numerators (the numbers at the top of the fraction) together.

For example 2/5+1/5=3/5. Here we have added the numerators 2 and 1 to make 3. The denominators are not added together and remain the same.

If the denominators are not the same, we need to make them the same. This is done by multiplying each of them by a common factor. 

For example, if we had 2/5+1/3 we would need to make the 5 and 3 the same number. This would be done by multiplying the 5 by 3 and the 3 by 5 to make both of the denominators 15. When multiplying the denominators, we also mulitply the numerators by the same number.

So, 2x3=6 and 5x3=15 which gives up 6/15 for the first fraction. Then 1x5=5 and 3x5=15 which gives us 5/15 for the second.

This leave us with 6/15+5/15. We then add the numerators to get 11/15.

Answered by Katie H. Maths tutor

4017 Views

See similar Maths 11 Plus tutors

Related Maths 11 Plus answers

All answers ▸

Margret wants to share £36 in a ratio of 3:4 between her two grandchildren, Anna and Katie. How much money will Katie get?


How many thirds are there in 8? a)3 b)24 c)9 d)22 e)4


There are 8 pink frogs in a pond, 25 blue frogs, 12 red frogs and 5 orange frogs. What percentage are pink?


The cost of one original glazed doughnut is £1.45. a) Find the cost of twelve doughnuts. The doughnut seller is offering customers a special deal: “Twelve doughnuts for £9.45” b) How much will each customer save?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences