Explain how to solve problems where the percentage part and size is known but the whole is unknown

Maths

In this unit pupils will explain what percent means and how to represent a percentage in different ways. They will learn how to convert percentages to decimals and fractions and solve conversion problems. In the future unit pupils will interpret and construct pie charts and line graphs. They will read scales  linked to fractions angles percentages and understanding proportional relationships.

In the prior unit pupils learned how to multiply 2 unit fractions and 2 non-unit fractions. They learned how to divide a unit fraction and a non-unit fraction by a whole number. In this unit pupils will explain what percent means and how to represent a percentage in different ways. They will learn how to convert percentages to decimals and fractions and solve conversion problems.

Understanding percentages

If I know a part, I can work out the whole. Match the parts of the sentence correctly. 

Lucas has read 25% of his book. He has read 64 pages. His book is {{ }} pages long.

Aisha thinks of a number. 20% of her number is 104      What is her number?

Lucas has read 75% of his book. This is 90 pages. How many pages are in his book? {{ }} pages

Aisha thinks of a number. 40% of her number is 72     What number is Aisha thinking of?

Lucas takes part in a race. He has run 30% of the race which is 600 m     What is the distance of the whole race? {{ }} m

If 100% of an amount is 320 km, find these percentages.

10% of a race is 1.5 km     Calculate these percentages of the race.

Aisha’s battery has 61% of 600 minutes left.  Complete each step of the table to calculate 61% of 600 minutes. {{ }} minutes

Lucas needs to find the number of children who cycled to school. Look at the pie chart and complete each step of the table to calculate 21% of 400 children {{ }} 

Look at the table and find the missing percentage.  18 = {{ }}% of 60

Use the table to calculate the missing percentage.     440 = {{ }}% of 800

Starter Quiz