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

Ordering

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?