Page 48 - Mathematics

Solution
(i) 35.49643 rounded off to the nearest thousandths is 35. 496.
(ii) 274 rounded off to the nearest tens is 270.
(iii) 3.2743 rounded off to the nearest hundredths is 3.27.
(iv) 856,145 rounded off to the nearest thousands is 856,000.
(v) 42.245468 rounded off to the nearest thousandths is 42.245.

(b) If the digit to the right of a rounding digit is greater than 5, then 1 is added to
the rounding digit and each digit to the right is replaced by zero.

Tanzania Institute of Education
Example 3.3

Round off:
(i) 0.267 to nearest tenths.
(ii) 17.82 to the nearest ones.
(iii) 63 504 to the nearest thousands.

Solution
(i) 0.267 to the nearest tenths is 0.3.
(ii) 17.82 rounded off to the nearest ones is 18.
(iii) 63 504 rounded off to the nearest thousands is 64 000.

Example 3.4

The population of a certain country in 1967 census showed that there were
5,834,875 men and 6,111,188 women. Round off the figures to the nearest
millions.

Solution
5,834,875 men is rounded off to the nearest millions as 6,000,000 men (1 is
added to 5 because the digit on the right of 5 is 8).
Mathematics Form One (6 remain unchanged since the digit on the right of 6 is 1 which is less than
6,111,188 women is rounded off to the nearest millions as 6,000,000 women

5 and each digit on the right of 6 is replaced by zero).

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Mathematics form 1.indd 42
Mathematics form 1.indd 42 25/10/2024 09:51:13