To calculate the number of sig figs
1. Count ALL nonzero numbers
2. If the zero is between 2 numbers, count it
3. If in a decimal the zero is at the end, count it
4. In a decimal all the zeros before the first nonzero number are placeholders and don't count them
5. In a number greater than zero all zeros AFTER the last nonzero number are placeholders and don't count them.
A - 5
B - 2
C - 3
D - 1
E - 4