Math for Life - Life: The Science of Biology, Seventh ... - WH Freeman

Math for LifeTOPIC 3: NUMERICAL DATA / Page 9READING AND REPORTING NUMERICAL DATA – Try It OutEXERCISE I: How many significant digits should you use when reporting valuesmeasured in the following ways:A. 250 mL measured using a pipette marked in 10 mL incrementsB. 0.8 mL measured using a 1 mL pipette marked in 0.1 mL incrementsC. 1.5 grams measured using a digital balance that reports three decimal placesD. An absorbance of 1.450 using a spectrophotometer that reports three decimalplacesE. A temperature of 350 K using a thermometer that reports one decimal placeF. Half a meter measured using a meter stick divided into cm incrementsG. A weight of 56.6 kg measured using a digital scale that reports two decimalplacesEXERCISE II: You have created a solution by pipetting 1.0 mL of water into a tube,then adding 1.26 x 10 −3 mg of NaCl. How many significant digitsshould you use when reporting the concentration of this solution inmg/mL?EXERCISE III: To determine the area of a rectangular plot of land, you measure thelength of the two sides and find them to be 20.8 m and 9.1 m. Howmany significant digits should you use when you report the area ofthe plot?BACKTOCNEXT