Question

Write $35.869, 0.008426, 4.952 and 382.7$ correct to three significant figures.

Accepted Answer

We start counting significant figures at the first non-zero digit. All non-zero digits and any zeros contained between two non-zero digits are significant.
If the number next to the significant figure is equal to or more than $5$ , then preceding digit is increased by $1$ .
The first significant figure of $35.869$ is $3$ .

Therefore, the third significant figure in $35.869$ is $8$ .

Here the next number is $6$ which is more than $5$ .

$∴ 35.869 \to 35.9$

The first significant figure of $0.008426$ is $8$ .

Therefore, the third significant figure in $0.008426$ is $2$ .

Here the next number is $6$ which is more than $5$ .

$∴ 0.008426 \to 0.00843$

The first significant figure of $4.952$ is $4$ .

Therefore, the third significant figure in $4.952$ is $5$ .

Here the next number $(2)$ is not large enough to round up.

$∴ 4.952 \to 4.95$

The first significant figure of $382.7$ is $3$ .

Therefore, the third significant figure in $382.7$ is $2$ .

Here the next number is $7$ which is more than $5$ .

$∴ 382.7 \to 383$

R K Bansal Solutions for Chapter: Decimal Fractions, Exercise 5: EXERCISE 4(E)

R K Bansal Mathematics Solutions for Exercise - R K Bansal Solutions for Chapter: Decimal Fractions, Exercise 5: EXERCISE 4(E)

Questions from R K Bansal Solutions for Chapter: Decimal Fractions, Exercise 5: EXERCISE 4(E) with Hints & Solutions

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