Percentages Learning objective We are learning to: • solve problems involving the calculation of percentages (e.g. of measures, such as 15% of 360) and the use of percentages for comparison (e.g. to find a percentage of a price).
What pupils already know • Pupils are secure with recognising the per cent symbol (%) and understand that per cent means ‘number of parts per hundred’. • They can write percentages as a fraction with the denominator one hundred, and as a decimal.
Key vocabulary percentage, discount, reduce, increase
Teaching notes • Explain that there are different ways of finding a percentage of an amount. Example: What is 40% of £50? Method 1: Convert the percentage to a fraction and find the fraction of the amount. 40% = 1 5
40 100
=
2 5
of £50 = £50 ÷ 5 = £10
Therefore,
2 5
= £10 × 2 = £20
Method 2: Find 10% first by dividing by 10, and then use this to work out the total percentage. 10% of £50 = £5 Therefore 40% = £5 × 4 = £20
For pupils – Steps to success: 1. Method 1: convert the percentage to a fraction and find the fraction of the amount. 2. Method 2: find 10% first by dividing by 10, and then use this to work out the total percentage.
Independent activity Refer pupils to the Year 6 Mental Arithmetic Pupil Book, pages 36–37.
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