The length and breadth of a rectangular sheet are 16.2 cm and 10.1cm, respectively. The area of the sheet in appropriate significant figures and error is

(i)In multiplication the answer is rounded off to the same number of significant figures as possessed by the least precise term used in the calculation.

(ii)The final result must contain as many significant figures as are in the original number with the least significant figures.

No. of significant figures in 16.2 is 3 and in 10.1 is 3. Here both are the least precise terms used. Therefore, the answer must contain 3 significant figures.

So, rounding off the answer to 3 significant figures we get

Now error,

If is the error in the area, be the error in length and be the error in breadth, then relative error is calculated as .

(For the formula part refer to

NCERT class 11 part 1 unit

and measurement chapter)

In dimensional analysis, in multiplication the answer is rounded off to the same number of significant figures as possessed by the least precise term used in the calculation. Here 0.1 has least precision and has 1 significant figure. Therefore,

(By rounding off to one significant figure)

Area,