Write each fraction as a fraction with denominator 12.
(a)Write 1/3 with denominator 12.(1)
(b)Write 5/6 with denominator 12.(1)
(c)Write 1/4 with denominator 12.(1)
(d)Write 7/12 with denominator 12.(1)
2
Calculate and simplify where possible: 1/2 + 1/6.
(2)
3
Add or subtract. Give your answers in simplest form.
(a)3/8 + 1/4(1)
(b)7/10 - 1/5(1)
(c)5/12 + 1/3(1)
4
Write each mixed number as an improper fraction.
(a)Write 2 1/3 as an improper fraction.(1)
(b)Write 3 2/5 as an improper fraction.(1)
5
Add these mixed numbers: 2 1/2 + 2 2/3. Give your answer as a mixed number in simplest form.
(3)
6
Work out 4 2/3 - 1 5/6. Give your answer in simplest form.
(4)
7
A recipe needs 1 3/4 cups of flour. Jake has already put in 2/3 cup. How much more flour does he need?
(2)
8
Simplify fully and show working: 3/5 + 7/15 - 1/3.
(3)
9
A class collects 3/4 kg of food, 5/6 kg of supplies and 2/3 kg of clothing. Find the total weight collected. Give your answer as a mixed number in simplest form if necessary.
(4)
10
Subtract and simplify: 11/6 - 4/3.
(3)
11
Write each of these as a fraction in simplest form: 8/12 - 1/4.
(2)
12
Olivia cycles 2 1/2 km before breakfast and 3 3/4 km after school. How far does she cycle in total? Give your answer as a mixed number.
(3)
13
Calculate and simplify: 7/9 + 2/3 + 1/6.
(4)
14
A baker uses 1 2/3 kg of sugar for one batch and 2 1/2 kg for another batch. How much more sugar is used in the second batch than the first? Give your answer in simplest form.
(3)
15
Work out and simplify: 2 3/5 + 4 4/5 - 1 7/10.
(4)
16
Simplify fully: (3/4 + 2/3) - (5/12).
(3)
17
Three friends share a 5 1/3 litre juice box. Sarah drinks 1 1/4 litres and Amir drinks 1 2/5 litres. How much is left? Give your answer in simplest form.
(4)
18
Stretch: A mural is 7 1/2 metres long. Three painters paint sections measuring 1 7/10 m, 2 3/5 m and 1 4/15 m. Will the whole mural be painted? If not, how much remains unpainted? Give your answer in simplest form.
(5)
Mark scheme · KS3.M-N9 Fractions: Adding and Subtracting
Question 1
(a) B1 4/12 cao
(a) Answer: 4/12
(b) B1 10/12 cao
(b) Answer: 10/12
(c) B1 3/12 cao
(c) Answer: 3/12
(d) B1 7/12 cao
(d) Answer: 7/12
Question 2
M1 correct common denominator or method, e.g. 1/2 = 3/6 then 3/6 + 1/6
A1 2/3 cao
Answer: 2/3
Question 3
(a) B1 5/8 cao
(a) Answer: 5/8
(b) B1 1/2 cao
(b) Answer: 1/2
(c) B1 9/12 or simplified 3/4 cao
(c) Answer: 3/4
Question 4
(a) B1 7/3 cao
(a) Answer: 7/3
(b) B1 17/5 cao
(b) Answer: 17/5
Question 5
M1 convert to improper fractions or add whole and fraction parts correctly
M1 add fractions with common denominator (1/2 = 3/6, 2/3 = 4/6) and convert to mixed number if needed
A1 5 1/6 cao
Answer: 5 1/6
Question 6
M1 convert mixed numbers to improper fractions (4 2/3 = 14/3, 1 5/6 = 11/6) or equivalent method
M1 use common denominator: 14/3 = 28/6 then 28/6 - 11/6
M1 calculate difference 17/6
A1 2 5/6 cao
Answer: 2 5/6
Question 7
M1 convert to common denominator or convert mixed to improper, e.g. 1 3/4 = 7/4 and 2/3 = 8/12, 7/4=21/12