Adding and subtracting fractions

Hi all,


As promised, here is a little something extra to get your teeth in to if you want/ need a little extra practise in the fractions department.
This week we have been going over adding and subtracting fractions and we have come across a few golden rules to help us...

• The denominators must be the same before we can add or subtract- if they're different we need to find the lowest common multiple to take the place of the old ones and recalculate the numerators before we continue,

           e.g. 2/4 + 3/7
          We cannot do this as the denominators are different (4 and 7)
          The lowest common multiple of both of these numbers is 28 (4x7= 28; 7x4=28)

• Whatever we do to the bottom we must do to the top.

So because we multiplied the denominators by 7 and 4, we must do that to the top too which then leaves us with 14/28 + 12/28 which equals 26/28

• We can simplify fractions using the highest common factor of the numerator and denominator. So, the highest number that I can count in to reach both 26 and 28 is 2.

Now that we have recapped those, let's try some more fractions calculations:

Bring your answers in and I'll check them over for you!

If you still want more then I have attached some links below that you might want to check out... Sometimes it helps to hear things explained by different people in different ways!

https://www.youtube.com/watch?v=QLUE6VqqrWY  (adding and subtracting fractions)

https://www.youtube.com/watch?v=bcCLKACsYJ0 (adding and subtracting unlike fractions)

https://www.youtube.com/watch?v=pynfj2bYRms  (adding mixed numbers)

Miss Barrell