Can somebody please explain sig figs and dimensional ysis to me?

sig figs are easy... count the number of sig figs like this... pretend is a problem like 2.00g x .050g it would = 1.0 or 2 sig figs because all 0's count, except for the ones before actual numbers like 1,2,3 ETC. But all other zeros count... Also all real numbers that actually have numbers like 1,2,3 count as well. Its always the number that has the least sig figs that count the number of sig figs you can have in the answer.