Question

calculations involving multiple steps
this example shows another critical point about performing calculations in steps that involve multiple steps. make sure to keep more significant figures than required during each intermediate step and round your final answer only as the very last step! if you take the value displayed in your calculator and record it before proceeding to the next step, you may introduce round - off error with your final answer deviating from the correct answer. (tip: most calculators have an answer button (e.g. ans) that allows you to use the last number from the previous calculation.)
in part b, you are asked to calculate the volume of a rectangular prism that has a length of 4.4 cm, a width of 3.1 cm, and a height of 6.3 cm, which is found by multiplying the area of the base times the height. in part a it was correct to round the result to two significant figures (14 cm²), even finding the area was the final step for that problem. however, given that the result is now being used in the calculation for part b, you should use the full - precision value (13.64 cm²) and only round upon reaching the final value for the volume, which is now the final step of the calculation.

• part b

calculate the volume of a rectangular prism with a length of 4.4 cm, a width of 3.1 cm, and a height of 6.3 cm. (as before, you do not need to enter the units since they are provided to the right of the answer box.)

Explanation:

Step1: Calculate base area

$4.4\times3.1 = 13.64\ \text{cm}^2$

Step2: Calculate volume

$13.64\times6.3 = 85.932\ \text{cm}^3$

Step3: Round to 2 sig figs

$85.932\approx86\ \text{cm}^3$

Answer:

86