1. GCSE Higher Revision Starters 4

2. Grade D – One number as a % of another Write these as percentages 8 out of 10 3 out of 5 7 out of 25 17 out of 50 1 out of 20 124 out of 200 84 out of 400 In a class of 20 there are 8 boys. What percentage of the class are girls? A gardener plants 7 seeds and only 3 of them grow. What percentage of the seeds grew?

3. Grade D – One number as a % of another Write these as percentages 8 out of 10 3 out of 5 7 out of 25 17 out of 50 1 out of 20 124 out of 200 84 out of 400 In a class of 20 there are 8 boys. What percentage of the class are girls? A gardener plants 7 seeds and only 3 of them grow. What percentage of the seeds grew? 80% 60% 28% 34% 5% 62% 21% 40% 42.9%

4. Grade B Number – Standard Form Write these numbers into ordinary form 3 x 10 5 6.4 x 10 3 2.81 x 10 6 6 x 10 -2 5.9 x 10 -4 3.783 x 10 -7 Write these numbers into standard form 560000 3040 391000000 0.007 0.0000064 0.21 Calculate, giving your answers in standard form 3.4 x 10 2 + 4.18 x 10 4 2.11 x 10 5 - 9.6 x 10 3 4 x 10 -2 + 6.3 x 10 -1 5.7 x 10 5 - 2.6 x 10 -3

5. Grade B Number – Standard Form Write these numbers into ordinary form 3 x 10 5 6.4 x 10 3 2.81 x 10 6 6 x 10 -2 5.9 x 10 -4 3.783 x 10 -7 Write these numbers into standard form 560000 3040 391000000 0.007 0.0000064 0.21 Calculate, giving your answers in standard form 3.4 x 10 2 + 4.18 x 10 4 2.11 x 10 5 - 9.6 x 10 3 4 x 10 -2 + 6.3 x 10 -1 5.7 x 10 5 - 2.6 x 10 -3 3000006400 28100000.06 0.000590.0000003783 5.6 x 10 5 3.04 x 10 3 3.91 x 10 8 7 x 10 -3 6.4 x 10 -6 2.1 x 10 -1 4.214 x 10 4 2.014 x 10 5 3.4 x 10 -1 5.7 x 10 5

6. Grade B – Calculating with Standard Form Work these out without a calculator (3 x 10 5 ) x (2 x 10 3 ) (6 x 10 3 ) x (7 x 10 7 ) (3.2 x 10 2 ) x (5 x 10 8 ) (2 x 10 -2 ) x (4 x 10 7 ) (2.1 x 10 -5 ) x (2 x 10 -2 ) (8 x 10 -5 ) x (4 x 10 -4 ) Work these out without a calculator (8 x 10 9 ) ÷ (2 x 10 3 ) (9 x 10 12 ) ÷ (3 x 10 6 ) (2.6 x 10 3 ) ÷ (1.3 x 10 8 ) (6 x 10 4 ) ÷ (2 x 10 -5 ) (2 x 10 6 ) ÷ (4 x 10 2 ) (3.5 x 10 -4 )÷ (7 x 10 -6 ) A piece of paper weighs 3 x 10 -4 g. How much will 2.4 x 10 12 pieces of paper weigh? Work this out without a calculator.

7. Grade B – Calculating with Standard Form Work these out without a calculator (3 x 10 5 ) x (2 x 10 3 ) (6 x 10 3 ) x (7 x 10 7 ) (3.2 x 10 2 ) x (5 x 10 8 ) (2 x 10 -2 ) x (4 x 10 7 ) (2.1 x 10 -5 ) x (2 x 10 -2 ) (8 x 10 -5 ) x (4 x 10 -4 ) Work these out without a calculator (8 x 10 9 ) ÷ (2 x 10 3 ) (9 x 10 12 ) ÷ (3 x 10 6 ) (2.6 x 10 3 ) ÷ (1.3 x 10 8 ) (6 x 10 4 ) ÷ (2 x 10 -5 ) (2 x 10 6 ) ÷ (4 x 10 2 ) (3.5 x 10 -4 )÷ (7 x 10 -6 ) A piece of paper weighs 3 x 10 -4 g. How much will 2.4 x 10 12 pieces of paper weigh? Work this out without a calculator. 6 x 10 8 4.2 x 10 11 1.6 x 10 11 8 x 10 5 4.2 x 10 -7 3.2 x 10 -8 4 x 10 6 3 x 10 6 2 x 10 -5 3 x 10 9 5 x 10 3 5 x 10 720000kg