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Cotmanhay Junior School

Safe, Happy Learning

Week 3 - 4 Percentages

National curriculum content


  • Solve problems which require answers to be rounded to specified degrees of accuracy
  • Recall and use equivalences between simple fractions, decimals and percentages, including in different contexts


Lesson objectives


  1. Recap - Understand percentages
  2. Fractions to percentages
  3. Equivalent FDP
  4. Order FDP
  5. Percentage of an amount (1)
  6. Percentage of an amount (2)
  7. Percentages – missing values


What we want children to know


  • They will use ‘number of parts per hundred’ alongside the % symbol.
  • How to convert fractions to equivalent fractions where the denominator is 100 in order to find the percentage equivalent.
  • Use their knowledge of common equivalent fractions and decimals to find the equivalent percentage.
  • Convert between fractions, decimals and percentages to enable them to order and compare them.
  • Use known fractional equivalences to find percentages of amounts.
  • Find multiples of 10% and other known percentages.
  • Explore different methods of finding certain percentages e.g. Finding 20% by dividing by 10 and multiplying by 2 or by dividing by 5. They also explore finding 5% by finding half of 10%. Using these methods, children build up to find percentages such as 35%.
  • Use their understanding of percentages to find the missing whole or a missing percentage when the other values are given.


What skills we want children to develop


Use knowledge to solve reasoning and problem solving questions such as:


Possible answers

Fill in the missing values to make this statement correct.

Can you find more than one way?


Make up an example/Give further examples


How many ways can you find 45% of 60?

Use similar strategies to find 60% of 45.

What do you notice? Does this always happen? Can you find more examples?


Missing numbers


50% of 40 = ____% of 80


___% of 40 = 1% of 400


10% of 500 = ____% of 100




Put the following amounts in order, starting with the largest.


23%, 5/8, 3/5, 0.8



Vocabulary/Mathematical Talk


  • What does the word ‘percent’ mean?
  • How can you convert tenths to hundredths?
  • Why is it easy to convert fiftieths to hundredths?
  • What other fractions are easy to convert to percentages?
  • How does converting a decimal to a fraction help us to convert it to a percentage?
  • How do you convert a percentage to a decimal?
  • Can you use a hundred square to represent your conversions?
  • Do you prefer to convert your numbers to decimals, fractions or percentages? Why?
  • Why do we divide a quantity by 2 in order to find 50%?
  • How do you calculate 10% of a number mentally?
  • What’s the same and what’s different about 10% of 300 and 10% of 30?
  • Is dividing by 10 and multiplying by 5 the most efficient way to find 50%? Explain why.
  •  Is dividing by 10 and multiplying by 9 the most efficient way to find 90%? Explain why.
  • How many ways can you think of to calculate 60% of a number?
  • If we know a percentage, can we work out the whole?
  • If we know the whole and the amount, can we find what percentage has been calculated?