and we had to round this was the question was to again

calculate the number of moles in each of the following masses
a)64.1 g of aluminum
b)28.1 g of silicon
c)0.255 g of sulfur
d)850.5 g of zinc
a) 64/27 = 2.4 mols b) 28.1g/28=1.0 mol c) 0.255/32=.0080 d)850.5/65 =13.076. I think i made some mistakes can u see if im on the right track or correct me if im wrong.. thanks in advance
also the answer has to be rounded and written in scientific notation form which ive failed and need help

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