Question

1. round off each of the answers correctly.

a. 8.7 g + 15.43 g + 19 g = 43.13 g
b. 4.32 cm × 1.7 cm = 7.344 cm²
c. 853.2 l - 627.443 l = 225.757 l
d. 38.742 m² ÷ 0.421 m = 92.023 75 m
e. 5.40 m × 3.21 m × 1.871 m = 32.431 914 m³
f. 5.47 m³ + 11 m³ + 87.300 m³ = 103.770 m³

Explanation:

Step1: Determine significant - figures for addition/subtraction

For addition and subtraction, the result should be rounded to the same number of decimal places as the measurement with the fewest decimal places.

Step2: Determine significant - figures for multiplication/division

For multiplication and division, the result should be rounded to the same number of significant figures as the measurement with the fewest significant figures.

Step3: Round a

In \(8.7\ g+15.43\ g + 19\ g = 43.13\ g\), \(19\) has no decimal places. So, round \(43.13\) to \(43\ g\).

Step4: Round b

In \(4.32\ cm\times1.7\ cm=7.344\ cm^{2}\), \(1.7\) has 2 significant figures. So, round \(7.344\) to \(7.3\ cm^{2}\).

Step5: Round c

In \(853.2\ L - 627.443\ L=225.757\ L\), \(853.2\) has one - decimal place. So, round \(225.757\) to \(225.8\ L\).

Step6: Round d

In \(38.742\ m^{2}\div0.421\ m = 92.02375\ m\), \(0.421\) has 3 significant figures. So, round \(92.02375\) to \(92.0\ m\).

Step7: Round e

In \(5.40\ m\times3.21\ m\times1.871\ m = 32.431914\ m^{3}\), \(5.40\) has 3 significant figures. So, round \(32.431914\) to \(32.4\ m^{3}\).

Step8: Round f

In \(5.47\ m^{3}+11\ m^{3}+87.300\ m^{3}=103.770\ m^{3}\), \(11\) has no decimal places. So, round \(103.770\) to \(104\ m^{3}\).

Answer:

a. \(43\ g\)
b. \(7.3\ cm^{2}\)
c. \(225.8\ L\)
d. \(92.0\ m\)
e. \(32.4\ m^{3}\)
f. \(104\ m^{3}\)