Cracking the SAT Chemistry Subject Test

counting    objects are infinitely  significant.    So  if  a   balanced    equation    calls

for 3   moles   of  carbon, we  can think   of  it  as  3.00    moles   of  carbon.

When multiplying and dividing, the result should have the same number of
significant figures as the number in the calculation that has the smallest number
of significant figures.

                                                0.352   ×   0.90876 =   0.320

                                864 ×   12  =   1.0 ×   10^4

7.0 ×   0.567   =   12

When adding and subtracting, the result should have the same number of
decimal places as the number in the calculation that has the smallest number of
decimal places.

                                                26  +   45.88   +   0.09534 =   72

780 +   35  +   4   =   819

Remember: The result of a calculation cannot be more accurate than the least
accurate number in the calculation.

And one more thing to remember for test day. Accurate and precise do NOT
mean the same thing! Accuracy is a measure of how correct a measurement is,
compared to some standard, while precision is a measure of how exact a
measurement is, compared to the real value of the measurement.