3 Significant zeros Deciding whether zeros are significant

3 Significant zeros

Deciding whether zeros are significant is difficult because zeros can be used for counting OR they can be used as labels When are are zeros used not used significant? for significant? ascounting? labels? One example is is money, When such they asare as the areused counting two usedfor zeros ascounting “ 10” labels onhundred “ hundred dollar bills. Story Time

Suppose that you take your car to a mechanic, and he says the repair willbills cost about 500 50 $1 bills will cost about 5 $100 Suppose that after the repair is completed the mechanic charges How much money do you expect to spend? you 502 764 $100 49 51 52 499 501 $10 $1 bills? It that acceptable? No. Yes. The The You estimate expect wasto was about spend about 5 about 50 500 $100 5500 50 500 5$10 50 $1 $100 $10 $500 $1 bills, $1 bills, –sofive it so socan hundred ititcan notbe bedollars one twobills more less more 5 $100 bills 50 $10 bills 500 $1 bills $400 to $600 $490 to $510 $499 to $501 One zero is a label Neither zero is a label Both zeros are labels The other is for counting Both zeros are for counting So, one sig. fig. So, three sig. fig. So, two sig. fig.

Here are some examples Significant Zeros 10001 1000. Not significant Zeros 1000. 00015 1000 Are these Zeros Sig. or not Sig. number? Now, how many significant figures in each 1203 Sig. 5460. Sig. 1200 Not Sig. 2 . 00546 Not Sig. 3 1200. Sig. 4 5460 Not Sig. 3 . 1203 Sig. 4 50406 Sig. 5 . 1230 Sig. 4 54600. 00 Sig. 7 . 0123 Not Sig. 3 54600. 5 4 Sig. 4

Here are some examples Significant Zeros 10001 1000. Not significant Zeros 1000. 00015 Now, how many significant figures in each number? 12030 4 54060 4 1230 3 540. 60 5 . 001203 4 . 0540 3 12. 30 4 . 005600 4 . 05060 4 0. 0056 2 123. 00. 12030 5 5 1000