__1.1 Significant Figures (Part 2)__**1.**Perform combined operations (addition, subtraction, multiplication and division) involving numbers, the final answer is rounded off to specific significant figures.

Example:

Example:

Find the value of each of the following and give your answer correct to

**3**significant figures.(a) 261.9 + 75.6 × 0.7

(b) 0.062 × 30.12 + 1.268

(c)
$8.608\xf70.08-28.35$

(d) 0.846 ÷ 0.4 – 0.153 × 2

(d) 0.846 ÷ 0.4 – 0.153 × 2

**Solution:****(a)**261.9 + 75.6 × 0.7

= 261.9 + 52.92

= 314.82

= 315 (3 s. f.)

= 315 (3 s. f.)

**0.062 × 30.12 + 1.268**

(b)

(b)

= 1.86744 + 1.268

= 3.13544

= 3.14 (3 s. f.)

**$8.608\xf70.08-28.35$**

(c)

(c)

= 107.6 – 28.35

= 79.25

= 79.3 (3 s. f.)

= 79.3 (3 s. f.)

**$0.846\xf70.4-0.153\times 2$**

(d)

(d)

= 2.115 – 0.306

= 1.809

= 1.81 (3 s. f.)

**Example 1**:

Calculate the value of 5.33 + 0.33 × 17 and give your answer correct to

**three**significant figures.

Solution:Solution:

5.33 + 0.33 × 17

= 5.33 + 5.61

= 10.

**9**4= 10.9 (3 s. f.)

**Example 2**:

Calculate the value of 49.3567 + 16.73 ÷ 0.5 and give your answer correct to

**four**significant figures.

**Solution:**49.3567 + 16.73 ÷ 0.5

= 49.3567 + 33.46

= 82.8

__1__67= 82.82 (4 s. f.)

**Example 3**:

Calculate the value of 3.42 ÷ 12 × 3.7 and give your answer correct to

**four**significant figures.

Solution:Solution:

3.42 ÷ 12 × 3.7

= 1.05

= 1.055 (4 s. f.)__4__5
Example 1

5.33 + 0.33 × 17

= 5.33 + 5.61

=10.94 not 10.84

Dear Asrin Azis,

thanks for pointing out our mistake, correction had been made accordingly.