OCR GCSE Maths

Topic Questions

Rounding, Estimation & Bounds

1
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2 marks

A number, n, is rounded to 2 decimal places.
The result is 4.76

Using inequalities, write down the error interval for n.

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2
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2 marks

The length, L cm, of a line is measured as 13 cm correct to the nearest centimetre.

Complete the following statement to show the range of possible values of L


................. ≤ L < .................

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3a
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1 mark

Find the value of the reciprocal of 1.6
Give your answer as a decimal.

3b
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2 marks

Jess rounds a number, x, to one decimal place.
The result is 9.8

Write down the error interval for x.

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4
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2 marks

Jim rounds a number, x, to one decimal place.
The result is 7.2

Write down the error interval for x.

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5
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3 marks

By writing each number correct to 1 significant figure, find an estimate for this calculation.

fraction numerator 606.3 space cross times space 0.312 over denominator 19.93 end fraction

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6
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2 marks

Use the symbols less than space comma less-than or slanted equal to space comma equals space comma greater than space comma greater-than or slanted equal to or to complete this statement.

If x = 4.7, truncated to 1 decimal place, then 4.7 ............... x ............... 4.8

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7
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2 marks

The length, d, of Jamal’s car is 4.72 m, correct to 2 decimal places.

Complete the error interval for the length, d.

....................... less-than or slanted equal to space d space less than ........................ 

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8
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3 marks

Asha worked out fraction numerator 326.8 space cross times open parentheses 6.94 space minus space 3.4 close parentheses over denominator 59.4 end fraction

She got an answer of 19.5, correct to 3 significant figures.

Write each number correct to 1 significant figure to decide if Asha’s answer is reasonable.

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9
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2 marks

The length, L, of a steel rod is 8.3 m, correct to 1 decimal place.

Complete the error interval for length L.

............................ less-than or slanted equal to L less than ............................

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10
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1 mark

When rounded to 3 significant figures, x space equals space 6.37

Circle the correct error interval.

6.365 space less-than or slanted equal to space x space less than space 6.375 6.36 space less-than or slanted equal to space x space less than space 6.38
6.369 space less-than or slanted equal to space x space less than space 6.379 6.365 space less-than or slanted equal to space x space less than space 6.3749

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11
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1 mark

The height of a tree is 12 metres, correct to the nearest metre.

Circle the error interval.

11.5 m ⩽ height < 12.5 m 11.5 m ⩽ height ⩽ 12.5 m
11.5 m < height ⩽ 12.5 m 11.5 m < height < 12.5 m

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12
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2 marks

To the nearest 1000, there are 18 000 people at a festival.

i)

Write down the minimum possible number of people at the festival.

[1]

ii)

Write down the maximum possible number of people at the festival.

[1]

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13
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2 marks

The length of a table is 110 cm to the nearest cm

Complete the error interval.

.................cm ⩽ length < .................cm

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14a
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2 marks

The length of each side of a regular pentagon is 8.4 cm to 1 decimal place.

Complete the error interval for the length of one side.

....................cm ⩽ length < ....................cm

14b
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1 mark

Complete the error interval for the perimeter.

....................cm ⩽ perimeter < ....................cm

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15
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2 marks

Each side of a regular octagon has a length of 18 mm, correct to the nearest 0.5 mm

q4-4ma1-2h-qp-jan22-paper2-igcse-maths

i)
Write down the lower bound of the length of each side of the octagon.
[1]

ii)
Write down the upper bound of the length of each side of the octagon.
[1]

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16
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2 marks

The mass of a cat is 4.3 kg correct to 2 significant figures.

i)

Write down the upper bound of the weight of the cat.
 

........................... kg [1]

ii)

Write down the lower bound of the weight of the cat.
 

........................... kg [1]

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17
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2 marks

The length of a book is 33.8 cm, correct to one decimal place.

i)
Write down the lower bound of the length of the book.

.............................................. cm [1]

ii)
Write down the upper bound of the length of the book.

.............................................. cm [1]

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