Do trailing 0's sans decimal matter
no
Do trailing 0's with a decimal matter
yes
Do leading zeroes matter even after a decimal
no
do leading zeroes after a decimal matter
yes
Do zeroes in between matter
yes
Sig figs for addition/subtraction
Same number of post decimal sig figs as the original number with least post decimal sig figs
Sig figs for multiplication/division
Same number of total sig figs as smallest sig figs original number