Fraction arithmetic and percentage change
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Before you start
Grades 4–5You will need these in every question below.
- A1[1 mark]
Work out .
Answer
- A2[1 mark]
Write in its simplest form.
Answer - A3[1 mark]
Write as an improper fraction.
Answer - A4[1 mark]
Work out 15% of 80.
Answer - A5[1 mark]
Write as a percentage.
Answer
Examples, then your turn
Grades 5–6Your teacher works through each example with you. Then try the one beside it on your own.
Work out .
- B1[3 marks]
Work out .
Answer
Work out .
- B2[3 marks]
Work out .
Answer
Increase £320 by 15%.
- B3[2 marks]
Decrease £360 by 35%.
Answer
The price of a ticket rose from £40 to £46. Work out the percentage increase.
- B4[3 marks]
The number of members of a club fell from 250 to 215. Work out the percentage decrease.
Answer
Practice
Grades 5–7Each question asks for something different. Show your working.
- C1[2 marks]
Write 45 minutes as a fraction of 2 hours. Give your answer in its simplest form.
Answer
- C2[2 marks]
Write these numbers in order of size. Start with the smallest.
Answer - C3[2 marks]
Work out . Give your answer in its simplest form.
Answer - C4
There are 32 students in a class. of them walk to school, 25% come by bus and the rest come by car.
(a)[2 marks]How many of the students come by car?
Answer(b)[2 marks]What percentage of the class come by car?
AnswerTotal for C4: 4 marks - C5[1 mark]
Write down the reciprocal of .
Answer - C6[3 marks]
Asha scored 42 out of 56 in her first test and 54 out of 75 in her second test. In which test did she get the higher percentage? You must show your working.
Answer - C7[2 marks]
Work out .
Answer - C8[3 marks]
A water tank is full. After 36 litres are added, it is full. How many litres does the tank hold when it is full?
Answer - C9[2 marks]
Find the number that is exactly halfway between and .
Answer
Exam-style questions
Grades 6–9Answer every question in the space given. Show your working: most of the marks are for method.
- D1[3 marks]
Show that .
- D2
A shop buys a jacket for £80 and sells it for £120.
(a)[2 marks]Work out the profit as a percentage of the price the shop paid.
Answer(b)[3 marks]In a sale, the shop reduces its selling price of the jacket by 15%. Work out the profit in the sale as a percentage of the price the shop paid.
AnswerTotal for D2: 5 marks - D3[3 marks]
Sam says, "."
Explain why Sam is wrong, and work out the correct answer.
Answer - D4[4 marks]
Kerry has £2400. She gives of it to her brother. She gives 25% of what is left to her sister. Then she spends of what she has left.
How much money does Kerry have now?
Answer - D5[2 marks]
Jo's salary rises from £24 000 to £25 080. Show that this is an increase of 4.5%.
- D6
A rectangular garden is m long and m wide.
(a)[2 marks]Show that the area of the garden is 105 m².
(b)[4 marks]of the garden is to be sown with grass seed. A bag of seed covers 9 m² and costs £4.80. The shop takes 10% off the price when you buy 5 or more bags.
Work out the cost of the seed for the garden.
AnswerTotal for D6: 6 marks - D7[4 marks]
400 people were asked which hot drink they like best. of them said tea. 36% of the rest said coffee. Everyone else said neither.
What percentage of the 400 people said neither?
Answer - D8[3 marks]
Work out . Give your answer as a mixed number.
Answer - D9[4 marks]
Last year a café sold 1250 cups of coffee a week at £2.40 a cup. This year it sells 1400 cups a week at £2.70 a cup.
Work out the percentage increase in the money the café takes for coffee each week.
Answer - D10[3 marks]
A ribbon is 2.4 m long. Hasan cuts 45 cm off it. Then he cuts off of the ribbon that is left.
What fraction of the original ribbon is left now? Give your answer in its simplest form.
Answer
Extension
Grade 9 and beyondNo route is given. Spend five minutes on a problem before you look at a hint. The hints are on the last page of the worksheet, and you can use one at a time.
- E1[4 marks]
A unit fraction has 1 as its numerator, such as .
Find every way of writing as the sum of two different unit fractions.
Hint 1 · What to try
Call the larger fraction . It must be more than half of , but less than .
Hint 2 · The first line
Half of is , so is between and . That leaves or .
Hint 3 · The full method
and . So and are the only two ways.
Answer
- E2[3 marks]
A fraction and its reciprocal add up to . Find the fraction. Give every possible answer.
Hint 1 · What to try
Write the fraction as , so its reciprocal is . Add them.
Hint 2 · The first line
Hint 3 · The full method
So and will do: and . The fraction is , or its reciprocal , which works just as well.
Answer - E3[3 marks]
In a school, 45% of the students are boys. 20% of the boys and % of the girls play in the orchestra. Altogether, 25.5% of the students play in the orchestra.
Find the value of .
Hint 1 · What to try
Suppose the school has 100 students. Work out how many are boys and how many are girls.
Hint 2 · The first line
of boys is , and of the students play, so girls play.
Hint 3 · The full method
out of girls is , so .
Answer - E4[3 marks]
Work out the exact value of
Hint 1 · What to try
Work out each bracket as a single fraction.
Hint 2 · The first line
Hint 3 · The full method
Each numerator cancels with the denominator before it. Only the first numerator, 1, and the last denominator, 50, are left. The answer is .
Answer
How did it go?
Colour one circle on each line.
| Not yet | Nearly | Yes | |
|---|---|---|---|
| I can add, subtract, multiply and divide fractions and mixed numbers. | |||
| I can write one quantity as a fraction of another. | |||
| I can increase or decrease an amount by a percentage. | |||
| I can work out a percentage change and write one quantity as a percentage of another. |
Answers and mark scheme
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