Question

There are two rules for determining the number of significant figures: ) If there is no decimal point-start at the RIGHT and count, beginning with the first non-zero digit. Examples 340 30400 34955 2 sf. 3 sf. 5 sf 2) If there is a decimal point--start at the LEFT and count, beginning with the first non-zero digit. Examples 340 3 sf. 5 s.f. 5 s.f 2 sf. 30400. 0.34955 0.00040 Determine the number of significant figures (s.f.) in each of the following a) 921 b) 92100 3 e) 92100. S d) 0.000210 g) 93,000,003 e) 0.00219 3 93,000.000 2 h) 93000,000. There are also rules for reporting numbers when you multiply and/or divide: 2 1) Count the sig. figs. in the numbers you are multiplying and/or dividing. Your answer should be rounded off to the smallest number of sig. figs. in your problem. 88.3896" ---calculator answer Example: a) 28.33 x 3.12 4 s.f. 3 s.f. 6sf. so round to 3 s.f. Your answer will be reported as 884 b) 28.44 3.12 -calculator answer "9.080128205" 1 6 s.f. 4 s.f. 3 s.f. so round to 3 s.f. Your answer will be reported as 9.08 Reminder: Rounding-off rules: Go to next number. If it is 04, round down. If it is 5-9, round up. Report the answer to the following problems, paying particular attention to the correct number of sig. figs. a) 986.72/5.12 =/93 b) 497.7/3.0- 170 d) 400.20 x 3.010= 1205 c) 920.7/4.32= 213 40.65 f009430 x 43109 e) 98 x 0.006= O.b h) 9.0/30= g) 45 20x 0.0071 = O-32 j) 10./3= 300 i) 10. x 300.-

Answer 1

There are two rules for determining the number of significant figures: ) If there is no decimal point-start at the RIGHT and count, beginning with the first non-zero digit. Examples 340 30400 34955 2 sf. 3 sf. 5 sf 2) If there is a decimal point--start at the LEFT and count, beginning with the first non-zero digit. Examples 340 3 sf. 5 s.f. 5 s.f 2 sf. 30400. 0.34955 0.00040 Determine the number of significant figures (s.f.) in each of the following a) 921 b) 92100 3 e) 92100. S d) 0.000210 g) 93,000,003 e) 0.00219 3 93,000.000 2 h) 93000,000. There are also rules for reporting numbers when you multiply and/or divide: 2 1) Count the sig. figs. in the numbers you are multiplying and/or dividing. Your answer should be rounded off to the smallest number of sig. figs. in your problem. 88.3896" ---calculator answer Example: a) 28.33 x 3.12 4 s.f. 3 s.f. 6sf. so round to 3 s.f. Your answer will be reported as 884 b) 28.44 3.12 -calculator answer "9.080128205" 1 6 s.f. 4 s.f. 3 s.f. so round to 3 s.f. Your answer will be reported as 9.08 Reminder: Rounding-off rules: Go to next number. If it is 04, round down. If it is 5-9, round up. Report the answer to the following problems, paying particular attention to the correct number of sig. figs. 1.7x10 2 a) 986.72/5.12 =/93 b) 497.7/3.0- 170 d) 400.20 x 3.010= 1205 c) 920.7/4.32= 213 40.65 f009430 x 43109 e) 98 x 0.006= 0.b g) 45.20 x 0.0071 = 0-32 i) 10. x 300.= 30D 3.0x10 3 h) 9.0/3.0= 3.0 10./3= 3 All your remaining answers are correct.