Sig Figs

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