What does significant mean? It means the numbers that are
important. How do you determine which ones are important? Use
the table below. 1. All nonzero digits of a measurement are
significant. Ex. If a balance reads 283.47g then all numbers are
significant. 2. Zeros occurring between significant numbers are
significant Ex. The balance reads 50.63 g then all four numbers
are significant. 3. All final zeros past the decimal point are
significant 73.00 grams means that you have 73.00 grams, not
just 73 grams. It is much more precise, and therefore
significant 4. Zeros used as placeholders are NOT significant.
“300” has one significant number, “3”. The zeros just hold the
place of the three. By writing “300” in scientific notation you
can get rid of the zeros – 3 x 102. If you indeed have 300 grams
or 300 people that you counted you can make the zeros
significant by writing – 3.00 x 102. Adding and Subtracting
significant numbers. The Key: The answer is only as precise as
the measurement that is the least precise