Priya has a square vegetable patch. Each side of the patch has length 9 m.
Diagram NOT accurately drawn
(Total for Question 6 is 2 marks)
7
A square rug has an area of 144 cm2. Work out the length of one side of the rug.
Diagram NOT accurately drawn
(Total for Question 7 is 2 marks)
8
Look carefully at the brackets in each calculation.
(a)Work out (-6)2(1)
(b)Work out -62(1)
(Total for Question 8 is 2 marks)
9
Work out each cube root.
(a)cbrt(-27)(1)
(b)cbrt(-1000)(1)
(Total for Question 9 is 2 marks)
10
Remember to use the correct order of operations.
(a)Work out 4 + 32(2)
(b)Work out (4 + 3)2(2)
(Total for Question 10 is 4 marks)
11
Work out the value of each expression, using the correct order of operations.
(a)2 x 52 - 32(2)
(b)20 - 2 x 32(2)
(Total for Question 11 is 4 marks)
12
Use estimation to answer each part.
(a)√30 lies between which two consecutive whole numbers?(1)
(b)√90 lies between which two consecutive whole numbers?(1)
(Total for Question 12 is 2 marks)
13
For each statement, write True or False.
(i)√25 = 5(1)
(ii)32 = 6(1)
(iii)√0 = 0(1)
(iv)1100 = 1(1)
(Total for Question 13 is 4 marks)
14
Simplify each expression, leaving your answer as a single power.
(a)a4 x a3(1)
(b)y5 x y(1)
(Total for Question 14 is 2 marks)
15
Simplify each expression, leaving your answer as a single power.
(a)b7 / b2(1)
(b)c6 / c6(1)
(Total for Question 15 is 2 marks)
16
Look at the pattern of powers to help you answer this question.
(a)Work out 80(1)
(b)Work out 150(1)
(c)Explain why any non-zero number raised to the power 0 is equal to 1.(2)
(Total for Question 16 is 4 marks)
17
Four identical square tiles, each with area 100 cm2, are arranged edge-to-edge (2 tiles by 2 tiles) to form one larger square.
Diagram NOT accurately drawn
(Total for Question 17 is 3 marks)
18
Show that 42 + 32 = 52
(Total for Question 18 is 2 marks)
19
Tom says: "√16 + √9 = √25". Explain why Tom is wrong.
(Total for Question 19 is 2 marks)
20
Simplify d3 x d4 / d2, leaving your answer as a single power.
(Total for Question 20 is 2 marks)
Mark scheme · 1.9 Powers and Roots
Question 1
(a) B1 4 cao
(a) Answer: 4
(b) B1 100 cao
(b) Answer: 100
(c) B1 25 cao
(c) Answer: 25
(d) B1 1 cao
(d) Answer: 1
Question 2
(a) B1 6 cao
(a) Answer: 6
(b) B1 8 cao
(b) Answer: 8
(c) B1 1 cao
(c) Answer: 1
(d) B1 11 cao
(d) Answer: 11
Question 3
(a) B1 8 cao
(a) Answer: 8
(b) B1 27 cao
(b) Answer: 27
(c) B1 1000 cao
(c) Answer: 1000
Question 4
B1 B (36) cao
Answer: B) 36
Question 5
(a) B1 10 cao
(a) Answer: 10
(b) B1 1000 cao
(b) Answer: 1000
(c) B1 1 cao
(c) Answer: 1
Question 6
M1 9 x 9 (or 92) seen
A1 81 m2 cao (units required)
Answer: 81 m2
Question 7
M1√144 seen or correct method to find the side length
A1 12 cm cao (units required)
Answer: 12 cm
Question 8
(a) B1 36 cao
(a) Answer: 36
(b) B1 -36 cao (the power applies to 6 only, then negate)
(b) Answer: -36
Question 9
(a) B1 -3 cao
(a) Answer: -3
(b) B1 -10 cao
(b) Answer: -10
Question 10
(a) M1 32 = 9 evaluated before the addition
(a) A1 13 cao
(a) Answer: 13
(b) M1 4 + 3 = 7 evaluated before the squaring
(b) A1 49 cao
(b) Answer: 49
Question 11
(a) M1 52 = 25 and 32 = 9 both evaluated (or 2 x 25 = 50 seen)
(a) A1 41 cao
(a) Answer: 41
(b) M1 32 = 9 and 2 x 9 = 18 seen
(b) A1 2 cao
(b) Answer: 2
Question 12
(a) B1 5 and 6 (both required), oe with correct reasoning e.g. 25 < 30 < 36
(a) Answer: 5 and 6
(b) B1 9 and 10 (both required), oe with correct reasoning e.g. 81 < 90 < 100
(b) Answer: 9 and 10
Question 13
(i) B1 True cao
(i) Answer: True
(ii) B1 False cao
(ii) Answer: False
(iii) B1 True cao
(iii) Answer: True
(iv) B1 True cao
(iv) Answer: True
Question 14
(a) B1 a7 oe
(a) Answer: a7
(b) B1 y6 oe
(b) Answer: y6
Question 15
(a) B1 b5 oe
(a) Answer: b5
(b) B1 1 cao (accept c0)
(b) Answer: 1
Question 16
(a) B1 1 cao
(a) Answer: 1
(b) B1 1 cao
(b) Answer: 1
(c) B1 correct reference to a pattern or index law, e.g. 23=8, 22=4, 21=2, 20=1 (dividing by the base each time), or bn / bn = b0 and any number divided by itself = 1
(c) B1 correct conclusion linking the pattern/law to the value 1, oe
(c) Answer: Any non-zero number to the power 0 equals 1, e.g. because bn / bn = bn-n = b0, and any number divided by itself is 1
Question 17
M1√100 = 10 cm, the side length of one small tile
M1 20 cm (2 x 10) identified as the side length of the larger square
A1 400 cm2 cao (units required)
Answer: 400 cm2
Question 18
B1 42 + 32 = 16 + 9 = 25 shown
B1 52 = 25 stated, so both sides are equal, cso
Answer: 25 = 25, so the statement is true
Question 19
M1√16 = 4 and √9 = 3 (so LHS = 7), and √25 = 5 (RHS), both evaluated
A1 correct conclusion that 7 is not equal to 5, so Tom is wrong, oe with correct supporting working
Answer: Tom is wrong because √16 + √9 = 4 + 3 = 7, but √25 = 5, and 7 is not equal to 5
Question 20
M1 correct combination of the powers, e.g. d3+4-2 or d7 / d2 seen