Question

To what decimal place should each answer be rounded? How many significant figures does the rounded answer have? 101 cm − 99.1 cm = 1.9 cm (unrounded) After rounding, the answer should be reported to the tenths place and thus has significant figures . 0.5 atm + 9.8 atm = 10.3 atm (unrounded) After rounding, the answer should be reported to the tenths place and thus has 2 siginificant figures .

Answer 1

Answer :

The answer will be, 2 cm and the number of significant figures is, 1

The answer will be, 10.3 cm and the number of significant figures are, 3

Explanation :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

The rule apply for the addition and subtraction is :

The least precise number present after the decimal point determines the number of significant figures in the answer.

(1) As we are given:

$101cm-99.1cm=1.9cm$

In the given expression, 101 has 3 significant figures and 99.1 has 3 significant figures. From this we conclude that least precise number present after the decimal point is 0 that means there is no number after decimal.

Thus, the answer will be, 2 cm and the number of significant figures is, 1

(2) As we are given:

$0.5atm+9.8atm=10.3atm$

In the given expression, 0.5 has 1 significant figures and 9.8 has 2 significant figures. From this we conclude that least precise number present after the decimal point is 1.

Thus, the answer will be, 10.3 cm and the number of significant figures are, 3