Year 6

We can calculate percentages of whole numbers

Year 6 Unit 12

What we are learning:

• We are learning to find the percentage of a number or a group of objects, without a calculator, and then with a calculator.
• Percentages are all around us, especially when we go shopping, but also in the news too.
• The link to work on fractions is essential to understanding percentages.
  Remember that 1% = 1/100 (one hundredth, or one part out of a hundred)
  Therefore 100% is 100/100 (one hundred parts out of a hundred, or the ‘whole’)
  If we said that 100% of fans were wearing blue scarves then every single one of them would be wearing a blue scarf! If we said that in the Sale there was a 100% reduction in price, then we would not pay anything for the goods!
• To find a percentage of a whole number we can divide it by 100 and then multiply the answer by the percentage that we want.
• 12% of £50 can be calculated as follows:
  £50 ÷ 100 = £0.50 (which is 1%)
  £0.50 x 12 = £6.00 (which is 12 % of £50)
• If we have a calculator the process is even faster.
• The keys we need to use for the same calculation are:
  50 x 12%
  this will give us the same answer, 6.0 or £6 in this case.
  If we want to calculate 35% of 700 we use the keys:
  700 x 35% and the answer displayed will be 245
  We could get to the same answer on paper by working out:
  700 ÷ 100 x 35

Activities you can do at home:

Look for the use of percentages all around you in shops, in newspapers, on television, on the radio.
Have a go at the Activity sheet, and if you are confident try the Extension Activity.

Good questions to ask:

Why do you think we use percentages so much?
Would a sale with 50% off be better than one with 20% off the price? Why?
What fraction is the same as 50%?
What fraction is the same as 25%?

If your child:

Can calculate percentages but is not sure what they mean
Talk about percentages in real life a lot.
Look at what VAT as a percentage does to different prices, from less expensive objects to very expensive objects.
Look at sale prices to see how much you are saving as a result of the percentage taken off.