Work out 30% of 140 using the percentage key on your calculator.
(Total for Question 6 is 1 mark)
7
Four students each carry out a calculation on their calculator. Work out the result of each calculation.
(a)Priya stores 18.5 in her calculator's memory using M+, then recalls the memory and multiplies by 4. Work out her result.(1)
(b)Work out -3 x (5 - 9).(1)
(c)Work out √196 - 8.(1)
(d)Give 7/9 as a decimal correct to 3 decimal places.(1)
(Total for Question 7 is 4 marks)
8
Work out 1/0.4 + 1/8, using the reciprocal key on your calculator.
(Total for Question 8 is 2 marks)
9
Use your calculator to work out (2.5 x 106) x (4 x 103). Give your answer in standard form.
(Total for Question 9 is 2 marks)
10
Ffion uses her calculator to work out 4.5 x 3.2. She then uses the ANS key to subtract 2.6 from this answer. Work out her final result.
(Total for Question 10 is 2 marks)
11
Work out √225 + cube root(64).
(Total for Question 11 is 2 marks)
12
Kwame wants to work out 42 / (3 + 4). He types 42 / 3 + 4 into his calculator and gets 18. Explain the mistake Kwame has made, and work out the correct answer.
(Total for Question 12 is 3 marks)
13
Work out 4 1/3 - 1 3/4, giving your answer as a mixed number. You may use the fraction key on your calculator.
(Total for Question 13 is 3 marks)
14
Work out √52.9 x 3.6, giving your answer correct to 3 significant figures.
(Total for Question 14 is 3 marks)
15
A rectangle has been measured with length 8.4 cm and width 5.6 cm, each correct to 1 decimal place. Use your calculator to work out the upper bound for the area of the rectangle, giving your answer to 2 decimal places.
(Total for Question 15 is 3 marks)
16
Show that (5 + 2sqrt(3))(5 - 2sqrt(3)) = 13. Hence use your calculator to find the value of 1/(5 - 2sqrt(3)), giving your answer correct to 3 significant figures.
(Total for Question 16 is 4 marks)
Mark scheme · 2.2DB Using a Calculator: Fluency and Exam Drill (Part 2)
Question 1
B1 10.15 cao
Answer: 10.15
Question 2
B1 9.6 cao
Answer: 9.6
Question 3
B1 44 cao
Answer: 44
Question 4
B1 7 cao
Answer: 7
Question 5
B1 7/12 cao
Answer: 7/12
Question 6
B1 42 cao
Answer: 42
Question 7
(a) B1 74 cao
(a) Answer: 74
(b) B1 12 cao
(b) Answer: 12
(c) B1 6 cao
(c) Answer: 6
(d) B1 0.778 awrt 3 d.p.
(d) Answer: 0.778
Question 8
M1 one correct reciprocal seen, e.g. 1/0.4 = 2.5 or 1/8 = 0.125
A1 2.625 cao
Answer: 2.625
Question 9
M1 correct unrounded value 10000000000 seen (or equivalent working)
A1 1 x 1010 cao (correct standard form)
Answer: 1 x 1010
Question 10
M1 4.5 x 3.2 = 14.4 seen (or correct use of ANS shown)
A1 11.8 cao
Answer: 11.8
Question 11
M1√225 = 15, or cube root(64) = 4, seen
A1 19 cao
Answer: 19
Question 12
M1 identifies that Kwame did not use brackets, so the calculator divided 42 by 3 before adding 4, instead of dividing 42 by the total (3 + 4) oe
M1 correct method: evaluate 3 + 4 = 7, then divide 42 by 7
A1 6 cao
Answer: Kwame's mistake: he did not enter brackets around (3 + 4), so his calculator divided 42 by 3 first and then added 4, instead of dividing 42 by the total (3 + 4). Correct answer: 6
Question 13
M1 convert to improper fractions or use fraction key: 13/3 - 7/4 oe
M1 common denominator 12 used, or show calculator method to reach 31/12
A1 2 7/12 cao
Answer: 2 7/12
Question 14
M1√52.9 = 7.27(3...) seen (or full unrounded calculator value)
M1 correct unrounded product, e.g. 26.18... or 26.183... seen
A1 26.2 awrt 3 s.f. cao
Answer: 26.2
Question 15
M1 upper bounds identified: length 8.45 and width 5.65
M1 correct unrounded product 47.7425 (or awrt) seen
A1 47.74 awrt 2 d.p. cao
Answer: 47.74 cm2
Question 16
M1 use (a - b)(a + b) = a2 - b2 with a = 5, b = 2sqrt(3) (cso)
M1 evaluate a2 - b2 = 25 - 12 = 13 (cso)
M1 rationalise, or use calculator to evaluate 1/(5 - 2sqrt(3)) = (5 + 2sqrt(3))/13 oe