Question 1(a): [2 marks]
Choose the best estimate for 3.9 \times 11.1.
Answer type: Multiple choice type 1
A: 44
B: 4
C: 440
D: 400
ANSWER: A: 44
WORKING: \approx 4 \times 11 = 44
Question 1(b): [2 marks]
Choose the best estimate for 2001 \times 31.01.
Answer type: Multiple choice type 1
A: 6200
B: 50000
C: 62000
D: 620000
ANSWER: C: 62000
WORKING: \approx 2000 \times 31 = 62000
Question 1(c): [2 marks]
Choose the best estimate for 49.53 \times 120.12.
Answer type: Multiple choice type 1
A: 4800
B: 6000
C: 60000
D: 48000
ANSWER: B: 6000
WORKING: \approx 50 \times 120 = 6000
Question 2: [2 marks]
Tom sells 1506 books at a cost of £6.95.
Choose the best estimate for the total amount of money Tom has made from selling his books.
Answer type: Multiple choice type 1
A: £10500
B: £9000
C: £1050000
D: £900000
ANSWER: A: 10500
WORKING: \approx 1500 \times 7 = 10500
Question 3: [2 marks]
Sarah needs to buy 30 packs of printer paper and 42 printer ink cartridges.
Each pack of printer paper costs £1.75 and ink cartridges cost £4 each.
Choose the two best estimates for the amount these items will cost.
Answer type: Multiple choice type 1
A: £200
B: £204
C: £220
D: £228
ANSWER: C: £220, D: £228
WORKING: \approx (30 \times 2) + (40 \times 4) = 220
or \approx (30 \times 2) + (42 \times 4) = 228
Question 4(a): [3 marks]
Choose the best estimate for \dfrac{24.38 \times 3.1}{3.89 \times 2.1}.
Answer type: Multiple choice type 1
A: 9
B: 5
C: 90
D: 100
ANSWER: A: 9
WORKING: \approx \dfrac{24 \times 3}{4 \times 2} = \dfrac{72}{8} = 9
Question 4(b): [3 marks]
Choose the best estimate for \dfrac{30.11 + 19.3}{1.22 \times 5.23}.
Answer type: Multiple choice type 1
A: 1
B: 120
C: 10
D: 12
ANSWER: C: 10
WORKING: \approx \dfrac{30 + 20}{1 \times 5} = \dfrac{50}{5} = 10
Question 4(c): [3 marks]
Choose the best estimate for \dfrac{20.2 \times 99.5}{11.11 - 5.95}.
Answer type: Multiple choice type 1
A: 400
B: 24
C: 40
D: 200
ANSWER: A: 400
WORKING: \approx \dfrac{20 \times 100}{11 - 6} = \dfrac{2000}{5} = 400
Question 5:
Jake is buying tiles for his floor.
His floor is 5.78 m \times \, 7.98 m
Question 5(a): [2 marks]
Choose the best estimate for the area of Jake’s floor.
Answer type: Multiple choice type 1
A: 40
B: 48
C: 35
D: 42
ANSWER: B: 48
WORKING: \approx 6 \times 8 = 48
Question 5(b): [1 mark}
Was this estimate an over estimate or under estimate?
Answer type: Multiple choice type 1
A: Over estimate
B: Under estimate
ANSWER: A: Over estimate
WORKING: Numbers are rounded to higher numbers.
Question 6(a): [2 marks]
James runs half a mile and records his time at 6.23 minutes.
Choose the best estimate for how many minutes it would take James to run 10 miles.
Answer type: Multiple choice type 1
A: 2
B: 12
C: 140
D: 120
ANSWER: D: 120
WORKING: 10 miles is 20 times the amount he ran in 6.23 minutes.
\approx 6 \times 20 = 120
Question 6(b): [2 marks]
James goes for another for 1 mile and records his time as 12.89 minutes.
He estimates that he can run 10 miles in 2 hours.
Is James correct?
Answer type: Multiple choice type 1
A: Yes
B: No
ANSWER: B: No
WORKING: \approx 13 \times 10 = 130 minutes = 2 hours 10 minutes.
This estimate gives a longer time than 2 hours, so James is incorrect.
Question 7: [2 marks]
Jonah has 394 guests, and each requires one glass of juice each.
Choose the best estimate for the number cartons of juice he will need, if each carton has enough to fill 9.5 glasses.
Answer type: Multiple choice type 1
A: 4
B: 40
C: 400
D: 4000
ANSWER: B: 40
WORKING: \approx 400 \div 10 = 40.