Question #f6b61
1 Answer
Sig figs communicate about the tool which was used to make a measurement.
Imagine a balance that will read two digits after the decimal. A mass of an object could be read with this balance as 2.11g which would have three sig figs.
A different object could be measured with that same balance as 2.00g. We want to record that mass as 2.00g rather than just 2g to indicate to anyone who looks at our data that the tool we used to measure that mass of 2.00g could give us information to the level of 0.01g.
In other words, since the balance can give us information two places past the decimal, we need to record all measurements made with that balance to two places past the decimal.
NOTE: The final digit of a measurement is assumed to have uncertainty. If you record a mass as 2.00g it means that the uncertainty in the measurement was probably ±0.01g. If you record a measurement as just 2g, it means that the uncertainty of the measurement could be as much as ±1g. Hope this clears up some things about the importance of sig figs.
:)
