Why there is a need of rounding off figures during calculation?

Short/Brief Note

When performing calculations with measured quantities, the rule is that the accuracy of the final result is limited to the accuracy of the least accurate measurement.
In other words, the final result cannot be more accurate than the least accurate number involved in the calculation.
Sometimes, the final result of a calculation often contains figures that are not significant.
When this occurs, the final result is rounded off.

shaalaa.com

Is there an error in this question or solution?

Chapter 2: Introduction to Analytical Chemistry - Exercises [Page 23]

Chapter 2 Introduction to Analytical Chemistry
Exercises | Q 2. (I) | Page 23

What do you mean by significant figures?

Why is accurate measurement crucial in science?

Solve the following question:

Round off the following quantity to two significant figures:

25.55 mL

Solve the following question:

Round off the following quantity to two significant figures:

199 g

Solve the following question:

Round off the following quantity to three significant figures:

1.43 cm³

Solve the following question:

Round off the following quantity to three significant figures:

0.039 m

Solve the following question:

Round off the following quantity to three significant figures:

6.398 × 10^-3 km

Solve the following question:

Round off the following quantity to three significant figures:

79,000 m

Solve the following question:

Round off the following quantity to three significant figures:

23,642,000 mm

Express the following sum to the appropriate number of significant figures:

2.3 × 10³ mL + 4.22 × 10⁴mL + 9.04 × 10³ mL + 8.71 × 10⁵ mL