Today, we are going to continue to learn how to subtract fractions.
Have a look at the in focus question below.
What information do we know and how do you think we could solve this?
How much flour is in each bag and how much is being taken out?
How do you think we can work out how much flour would be left? What do you think the calculation would be?
Have a look below to see how to work this out and see if you were correct.
How do you think we can work out 2 ½ - 1 ¼?
Look at the 2 methods which have been shown above. Which method do you prefer?
In method 1, you can see that we have changed the denominators so they are both 4.
Once they have been made the same, we can subtract the whole numbers then subtract the fraction and we are left with 1 ¼.
How can we solve this calculation?
Can we make the denominators the same?
That’s right, we can multiply the 2 in ½ so if we multiply by 4 we can make 8. If we do the same to the top, 1 x 4 = 4.
We have now made the fraction 2 4/8 – 7/8.
We cannot calculate 4 – 7 therefore we need to convert this mixed fraction into an improper fraction.
Can you remember how to do this?
Well done, in the fraction 2 and 4/8 we can multiply 8 x 2 = 16 and add 4 which makes 20
We have now made 2 and 4/8 into 20/8 which we can takeaway from 7/8 which can be completed. The answer is 13/8.
This is still an improper fraction.
Can you convert this to a mixed fraction?
Well done if you got the answer 1 5/8.
Now, try the Guided Practice section below then complete worksheet 14 which will be sent to you on Seesaw.