Question

Calculate the area, with the appropriate number of significant figures, of a rectangular room that is 14.10 m wide by 15.0 m long. A. 212 m^2 B. 211.5 m^2 C. 29.1 m D. 29.10 m

Answer 1

Answer: Choice A) 212 square meters

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Explanation:

14.10 has four sig figs. The 0 at the end is significant. This measurement is accurate to the hundredths place. If the author wrote 14.1, then it would be accurate to the tenths place with three sig figs.

15.0 has three sig figs. The 0 is significant. If they wrote 15 or 15. then we'd be dealing with 2 sig figs instead; however they placed the 0 there to tell the reader "this measurement is accurate to the tenths place"

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Multiply the values given

14.10*15.0 = 211.5

Round that to three sig figs. We pick the smaller sig fig count to round to since we cannot be certain it is accurate to four sig figs. In a sense, we pick the weakest link and use that to determine rounding when it comes to multiplication and division.

This means 211.5 rounds to 212