Finding percentages of something

Present this problem to your learners or pose a problem with the same numbers but a different story.

Kegs hold 50 litres of beer.

There is 10% allowance for wastage. What a shame!

How much beer is wasted out of each keg?

Note: Wastage is loss of beer through pouring overflow, clearing the hose lines when kegs are changed and the beer left behind in the keg.

Ask the learners to solve the problem and share their strategies.

For example, “I know that 10% is one tenth and one tenth of 50 is 5 litres” or “10% is ten out of 100 so it must be 5 out of 50 litres.”

Present the problem using the strip diagram (Copymaster 4).