34.872 to 1 significant figure

Answer 1

34.872 rounded and chopped to 1 sig fig is 30. The previous answer 34.8 is wrong, 34.8 is 34.872 chopped to 3 sig figs.

Any digit in a number that is not zero is classed as a significant figure e.g. your number above has 5 sig figs but if it was 30.072 it would only have 3 sig figs: 3, 7 and 2. When someone asks something to be taken to n sig figs they mean the first n significant figures of the number i.e. 103.42 to 2 sig figs would be 103, not 100.

Also, incase you don't know what I mean when i used the terms rounded and chopped above, rounding is when you round the number either up or down to the nearest sig fig so your number rounded to 2 sig figs would be 35. Chopping however is when you take however sig figs you need and chop the rest of regardless of how close the n+1th digit is to a higher sig fig. e.g. 34.372 is 34 chopped to 2 s.f. but 34.872 is also 34 chopped to 2 s.f. in fact if a number is virtually the same as a higher number it will get chopped to a lower one e.g. 34.999999999999999 chopped to 2 s.f. is 34, not 35!