Page 50 - Mathematics

Example 3.7

Round off the following numbers according to the instruction.
(a) 3.6265 to the nearest thousandths.
(b) 2,500,000 to the nearest millions.

Solution
(a) 3.6265 to the nearest thousandths is 3.626 since the digit to the right of
the rounding digit (6) is 5 and all digits to the right of 5 are zeros.
(b) 2,500,000 to the nearest millions is 2,000,000 since the digit to the right
of the rounding digit (2) is 5 and all digits to the right of 5 are zeros.
Tanzania Institute of Education

Exercise 3.1

1. Round off each of the following numbers to the nearest thousands.
(a) 8,259 (d) 100,998 (g) 60,500
(b) 12,222 (e) 17,501 (h) 9,999
(c) 13,709 (f) 2,349,673 (i) 1,234,567
2. Round off each of the following numbers to the nearest ones.
(a) 41.4 (d) 0.8
(b) 0.49 (e) 0.379
(c) 2.613 (f) 2.55
3. Round off each of the following numbers to the nearest tens.
(a) 25.12 (d) 10.0089 (g) 20.17
(b) 16.15 (e) 50.408 (h) 311.114
(c) 28.929 (f) 33.456
4. The total mass of cotton harvested in a certain district was 17,816,273 kg.
Round off the mass to the nearest.
(a) Millions of kilograms (b) Thousands of kilograms
5. In 1983, the number of primary school pupils in a certain region was
Mathematics Form One (a) 38.5 4.1× (d) 10.3 4.4 × (f) 0.048 20.08×
237,268. Round off the number of pupils to the nearest thousands.
6. Find the value of each of the following, and round off the answers to the
nearest hundredths:

(e) 72 0.98×
(c) 2.5 43.642×

(b) 9.9 9.9×

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Mathematics form 1.indd 44
Mathematics form 1.indd 44 25/10/2024 09:51:13