Driving down the interstate, you see mile markers every certain amount of miles. Even when you pass a mile marker you still say your are at an estimated distance. When you pass the mile marker for mile 102, and you are asked where you are, you would say, “past mile 102,” rather than ,” 102.12434 miles.” Since we are unsure of the decimal section we cannot specify that and therefore can only discuss the 102.
The significant figures in a measurement consist of all the certain digits in that measurement plus one uncertain or estimated digit. So for the mile marker image above, the significant figures could be 135.0 which estimates one number past what is confirmed.
1. If you were to pass mile 143 on I-5 what mile would you say you were at?
2. Name other usages of significant figures in the real world?