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Rounding & bounds
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56 questions at your level
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Level 1
Level 2
Level 3
Level 4
Level 5
Rounding and significant figures
20 questions
Lesson
Not started
Mark as done
(a)
Round 4562 to 2 significant figures.
(b)
Round 0.030472 to 3 significant figures.
(c)
Round 18.965 to 1 decimal place.
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Level 3
3 marks
Start
→
Mark as done
x
=
5.3
x = 5.3
x
=
5.3
, correct to 1 decimal place. Write down the error interval for
x
x
x
.
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Level 3
2 marks
Start
→
Mark as done
The mass of a bag,
m
m
m
kg, is
12
12
12
kg correct to the nearest kilogram.
Write down the error interval for
m
m
m
.
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Level 3
2 marks
Start
→
Mark as done
A number,
w
w
w
, is rounded to
2
2
2
significant figures.
The result is
0.46
0.46
0.46
(a)
Write down the least possible value of
w
w
w
.
(1 mark)
Marek says,
"The greatest possible value of
w
w
w
is
0.4649
0.4649
0.4649
because
0.465
0.465
0.465
would round up to
0.47
0.47
0.47
"
(b)
Is Marek correct?
You must give a reason for your answer.
(1 mark)
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Level 3
2 marks
Start
→
Mark as done
Ivan orders
587
587
587
metres of fencing wire.
The wire costs £
3.84
3.84
3.84
for every
10
10
10
metres.
(a)
Work out an estimate for the total cost of the wire.
(3 marks)
(b)
Is your answer to part (a) an underestimate or an overestimate?
Give a reason for your answer.
(1 mark)
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Level 3
4 marks
Start
→
Estimation
15 questions
Lesson
Not started
Mark as done
Work out an estimate for the value of
48.6
×
21.2
9.7
\dfrac{48.6 \times 21.2}{9.7}
9.7
48.6
×
21.2
You must show your working.
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Level 3
3 marks
Start
→
Mark as done
Work out an estimate for the value of
19.6
×
5.3
\sqrt{19.6 \times 5.3}
19.6
×
5.3
You must show your working.
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Level 3
3 marks
Start
→
Mark as done
Work out an estimate for the value of
39.2
×
5.1
9.8
\dfrac{39.2 \times 5.1}{9.8}
9.8
39.2
×
5.1
You must show your working.
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Level 3
2 marks
Start
→
Mark as done
Work out an estimate for the value of
6.8
×
3.1
×
4.9
6.8 \times 3.1 \times 4.9
6.8
×
3.1
×
4.9
You must show your working.
●●●
●●
Level 3
2 marks
Start
→
Mark as done
Ivan orders
587
587
587
metres of fencing wire.
The wire costs £
3.84
3.84
3.84
for every
10
10
10
metres.
(a)
Work out an estimate for the total cost of the wire.
(3 marks)
(b)
Is your answer to part (a) an underestimate or an overestimate?
Give a reason for your answer.
(1 mark)
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●●
Level 3
4 marks
Start
→
Upper and lower bounds
23 questions
Lesson
Not started
Mark as done
The length of a shelf is 45 cm, correct to the nearest centimetre.
(a)
Write down the lower bound of the length.
(b)
Write down the upper bound of the length.
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Level 3
2 marks
Start
→
Mark as done
The mass of a cat is
2.7
2.7
2.7
kg, correct to
1
1
1
decimal place.
(a)
Write down the lower bound of the mass.
(b)
Write down the upper bound of the mass.
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Level 3
2 marks
Start
→
Mark as done
The side of a square is
5.4
5.4
5.4
cm, correct to 1 decimal place.
(a)
Write down the error interval for the side length,
s
s
s
cm. (2 marks)
(b)
Work out the lower bound for the perimeter of the square. (1 mark)
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Level 3
3 marks
Start
→
Mark as done
A rectangle has length
8.4
8.4
8.4
cm and width
5.6
5.6
5.6
cm, each measured correct to 1 decimal place.
Work out the upper bound for the area of the rectangle. (3 marks)
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Level 3
3 marks
Start
→
Mark as done
x
=
7.36
x = 7.36
x
=
7.36
correct to 2 decimal places.
y
=
4.9
y = 4.9
y
=
4.9
correct to 1 decimal place.
(a)
Write down the error interval for
y
y
y
. [2]
(b)
Work out the upper bound of
x
y
\dfrac{x}{y}
y
x
. Give your answer correct to 3 significant figures. [3]
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Level 3
5 marks
Start
→
Mark as done
A number,
w
w
w
, is rounded to
2
2
2
significant figures.
The result is
0.46
0.46
0.46
(a)
Write down the least possible value of
w
w
w
.
(1 mark)
Marek says,
"The greatest possible value of
w
w
w
is
0.4649
0.4649
0.4649
because
0.465
0.465
0.465
would round up to
0.47
0.47
0.47
"
(b)
Is Marek correct?
You must give a reason for your answer.
(1 mark)
●●●
●●
Level 3
2 marks
Start
→