Kwame records an overnight low temperature of -18.7 degrees C at a weather station in Fort William. Round -18.7 to the nearest whole number.
(Total for Question 8 is 1 mark)
9
Circle the number below that rounds to 3,600 when rounded to the nearest 100.
A) 3,542
B) 3,589
C) 3,651
D) 3,499
(Total for Question 9 is 1 mark)
10
A cinema chain reported 156,742 admissions across its screens last week. Complete the table by rounding 156,742 to each of the accuracies shown.
(a)Round 156,742 to the nearest 10.(1)
(b)Round 156,742 to the nearest 1,000.(1)
(c)Round 156,742 to the nearest 10,000.(1)
(Total for Question 10 is 3 marks)
11
Priya rounds 0.5471 to 3 significant figures and writes 0.548.
(a)State Priya's mistake.(1)
(b)Write down the correct answer.(1)
(Total for Question 11 is 2 marks)
12
Show that 0.0296 rounded to 2 significant figures is 0.030.
(Total for Question 12 is 2 marks)
13
A stationery order comes to 4.65 pounds, 7.28 pounds and 2.19 pounds for three separate items. Work out the exact total cost. Then estimate the total by rounding each cost to the nearest pound before adding, and state whether this estimate matches the exact total when the exact total is also rounded to the nearest pound.
(Total for Question 13 is 3 marks)
14
A minibus hire company works out 812.4 / 3.9 and gets an answer of 208.3. By rounding each number to 1 significant figure, estimate the value of 812.4 / 3.9, and state whether 208.3 is a reasonable answer.
(Total for Question 14 is 2 marks)
15
A charity fun run raises 3,460 pounds, to be shared equally between 7 local charities. Work out the exact amount each charity receives, then round your answer to the nearest penny to state the amount that will actually be paid to each charity.
(Total for Question 15 is 3 marks)
16
Round 3,500 to the nearest 1,000 and to the nearest 100. Explain why one of your two answers needed the 'round half up' rule to decide it, but the other did not.
(Total for Question 16 is 3 marks)
17
The diagram shows a thermometer scale marked in whole degrees Celsius from 10 to 20. The mercury level is shown resting at 16.7 degrees C. Round the temperature to the nearest whole number.
Figure (to be drawn): A vertical thermometer scale marked with gradation lines at every whole degree from 10 to 20 degrees C; the shaded mercury column rises to a level about seven tenths of the way between the 16 and 17 gradation lines, with a small arrow labelled '16.7 degrees C' pointing to the top of the shading.
(Total for Question 17 is 1 mark)
Mark scheme · 1.7DB Rounding: Fluency and Exam Drill (Part 2)
Question 1
B1 580 cao
Answer: 580
Question 2
B1 7,200 cao
Answer: 7,200
Question 3
B1 93,000 cao
Answer: 93,000
Question 4
B1 5.64 cao
Answer: 5.64
Question 5
B1 0.081 cao
Answer: 0.081
Question 6
B1 300 cao
Answer: 300
Question 7
B1 0.0030 cao
Answer: 0.0030
Question 8
B1 -19 cao
Answer: -19 degrees C
Question 9
B1 B (3,589) cao
Answer: B) 3,589
Question 10
(a) B1 156,740 cao
(a) Answer: 156,740
(b) B1 157,000 cao
(b) Answer: 157,000
(c) B1 160,000 cao
(c) Answer: 160,000
Question 11
(a) B1 identifies that the 4th significant figure is 1, which is less than 5, so the third significant figure (7) should stay the same, not round up to 8 oe
(a) Answer: Priya rounded up the third significant figure when she should not have: the digit after it is 1, which is less than 5.
(b) B1 0.547 cao
(b) Answer: 0.547
Question 12
M1 identifies the first 2 significant digits as 2 and 9, and notes the next digit 6 causes rounding up with a carry (9 rounds to 10) oe
A1 cso 0.030 cao
Answer: 0.030
Question 13
M1 exact total 4.65 + 7.28 + 2.19 = 14.12 shown
A1 estimate 5 + 7 + 2 = 14 (each cost rounded to the nearest pound before adding) cao
B1 states the estimate (14) matches the exact total rounded to the nearest pound (14.12 rounds to 14) oe
Answer: Exact total GBP14.12; estimate GBP14; yes, they match (both round to GBP14).
Question 14
M1 estimate using 800 / 4 = 200 oe
A1 conclude 208.3 is reasonable as it is close to the estimate cao
B1 notes that 7 x 494.29 = 3,460.03, which is 3 pence more than the 3,460 pounds raised, so rounding to the nearest penny does not exactly reconcile with the total oe
Answer: GBP494.29 to the nearest penny; 7 x 494.29 = GBP3,460.03, which is 3p more than the GBP3,460 raised, so the shares do not exactly reconcile with the total once rounded.
Question 16
M1 nearest 1,000 = 4,000 identified, recognising 3,500 is exactly halfway between 3,000 and 4,000
M1 nearest 100 = 3,500 identified, recognising 3,500 is already an exact multiple of 100
B1 explains that the round-half-up rule is only needed at the accuracy where the number sits exactly on a boundary (nearest 1,000 here), whereas 3,500 is already an exact hundred so no rounding decision arises there oe
Answer: nearest 1,000 = 4,000; nearest 100 = 3,500. The round-half-up rule was needed for the nearest 1,000 (3,500 is exactly halfway between 3,000 and 4,000), but not for the nearest 100 (3,500 is already an exact multiple of 100, so there is no rounding decision to make).