1 Estimation
1. (a) Round up 123.45 to 1 significant figure.
(b) Round off 123.45 to the nearest integer.
(c) Round down 123.45 to 1 decimal place.
[2014-3]
2. (a) Round up 265.473 to the nearest integer.
(b) Round down 265.473 to 1 decimal place.
(c) Round off 265.473 to 2 significant figures.
[2018-3]
3. (a) Round up 534.7698 to the nearest hundred.
(b) Round down 534.7698 to 2 decimal places.
(c) Round off 534.7698 to 2 significant figures.
[2020-3]
4. A pack of sea salt is termed regular if its weight is measured as 100 g correct to the nearest g.
(a) Find the least possible weight of a regular pack of sea salt.
(b) Is it possible that the total weight of 32 regular packs of sea salt is measured as 3.1 kg correct to the
nearest 0.1 kg? Explain your answer.
[2013-8]
5. A bottle is termed standard if its capacity is measured as 200 mL correct to the nearest 10 mL.
(a) Find the least possible capacity of a standard bottle.
(b) Someone claims that the total capacity of 120 standard bottles can be measured as 23.3 L correct to
the nearest 0.1 L. Do you agree? Explain your answer.
[2017-9]
6. 0.009049999 =
A. 0.00905 (correct to 3 decimal places).
B. 0.00905 (correct to 3 significant figures).
C. 0.00905 (correct to 6 decimal places).
D. 0.00905 (correct to 6 significant figures).
[PP-14]
7. 0.0322515 =
A. 0.032 (correct to 3 significant figures).
B. 0.0322 (correct to 4 decimal places).
C. 0.03225 (correct to 5 significant figures).
D. 0.032252 (correct to 6 decimal places).
[2012-13]
8. 0.0504545 =
A. 0.051 (correct to 2 significant figures).
B. 0.0505 (correct to 3 decimal places).
C. 0.05045 (correct to 4 significant figures).
D. 0.05046 (correct to 5 decimal places).
[2013-4]
9. 0.0023456789 =
A. 0.00235 (correct to 6 decimal places).
B. 0.002345 (correct to 6 decimal places).
C. 0.002346 (correct to 6 significant figures).
D. 0.00234568 (correct to 6 significant figures).
[2015-4]
10. 0.0765403 =
A. 0.076 (correct to 2 significant figures).
B. 0.0765 (correct to 3 decimal places).
C. 0.07654 (correct to 4 significant figures).
D. 0.076540 (correct to 5 decimal places).
[2016-4]
11. =
A. 0.0102 (correct to 3 significant figures).
B. 0.01025 (correct to 4 significant figures).
C. 0.01026 (correct to 5 decimal places).
D. 0.010266 (correct to 6 decimal places).
[2017-4]
12. If , which of the following is true?
A. x = 0.065 (correct to 2 decimal places)
B. x = 0.065 (correct to 2 sig. fig.)
C. x = 0.0656 (correct to 3 decimal places)
D. x = 0.0656 (correct to 3 sig. fig.)
[2019-6]
13. The lengths of the three sides of a triangle are measured as 15 cm, 24 cm and 25 cm respectively. If the
three measurements are correct to the nearest cm, find the percentage error in calculating the perimeter
of the triangle correct to the nearest 0.1%.
A. 0.8%
B. 2.3%
C. 4.7%
D. 6.3%
[SP-15]
14. The length of a piece of thin string is measured as 25 m correct to the nearest m. If the string is cut into
n pieces such that the length of each piece is measured as 5 cm correct to the nearest cm, find the
greatest possible value of n.
A. 445
B. 566
C. 567
D. 650
[2012-14]
15. There is a bag of white sugar. The weight of white sugar in the bag is measured as 5 kg correct to the
nearest kg. If the bag of white sugar is packed into n packets such that the weight of white sugar in each
packet is measured as 10 g correct to the nearest g, find the greatest possible value of n.
A. 429
B. 500
C. 578
D. 579
[2015-14]
16. The width and the length of a thin rectangular metal sheet are measured as 8 cm and 10 cm correct to
the nearest cm respectively. Let be the actual area of the metal sheet. Find the range of values of
x.
A.
B.
C.
D.
[2014-11]
17. In the figure, ABCDEFGH is an octagon, where all the measurements are correct to the nearest cm. Let
be the actual area of the octagon. Find the range of values of x.
A.
B.
C.
D.
[2018-14]
18. In the figure, PQRST is a pentagon, where all measurements are correct to the nearest cm. Let be
the actual area of the pentagon. Find the range of values of A.
A.
B.
C.
D.
[2020-14]
