Significant Figures

You should have noticed that the zeros in the previous question were not significant. Why? The answer lies in the reason they are written. They are only there as placeholders. Therefor, leading zeros are never significant. Lets try a few more.

It doesn't matter how many zeros I have in front of the number. They will never be counted as significant. What about zeros between non-zeros?

These zeros will always count toward your significant figure tally.

These zeros are the most challenging to count as they sometimes do and sometimes don't. The rule is, if there is a decimal point in the number, the trailing zeros count. Lets practice with some of these.

See what happened when I added the decimal? You went from 1 sig fig in the number 100, to 4 sig figs in the number 100.0 The decimal place is more than a placeholder. It lets the reader know that the number has that level of precision. Here are a few more practice problems using all of the rules.