Page 62 - Mathematics

(iii) Any digit from 1 to 9 appearing in a number is a significant figure.
(iv) When zeros are written to the right of the last non-zero digit of an
exact number, the zeros are not significant figures.
3. In decimals, any zero written to the left of the first non-zero digit is not
a significant figure.
4. All zeros that are on the right of the decimal point are significant, only if
a non-zero digit does not follow them.
5. When a zero is written at the end of an approximated decimal or number,
it is a significant figure.
6. All the zeros that are on the right of the last non-zero digit are significant
if they come from measurements.
Tanzania Institute of Education

Revision exercise 3

1. Round off each of the following numbers to the nearest hundredths.
(a) 8.648 (d) 31.7842
(b) 1.0544 (e) 19.6723

(c) 0.341 (f) 0.453
2. Round off each of the following numbers to the nearest millions and
thousands.

(a) 78,911,393 (d) 1,350,095,450
(b) 1,114,562 (e) 20,781,233

(c) 22,878,130
3. The population of children under the age of fifteen years in a certain
country in 2004 was 5,267,910. Round off the population to the nearest.

(a) Millions (b) Thousands (c) Hundreds
4. Express each of the following fractions in a decimal, correct to 4 significant

figures. (b) 70 (c) 1
Mathematics Form One 5. Write 86.463 correct to:
3
5
(a)
6
11

(a) 1 decimal place (c) 1 significant figure
(b) 2 decimal places (d) 2 significant figures

56

25/10/2024 09:51:16
Mathematics form 1.indd 56
Mathematics form 1.indd 56 25/10/2024 09:51:16