i need to know how to solve this chem question!?

Question

Gold costs $1250/oz. how many atoms of gold can you buy with two pennies. 1oz = 31.1g

Answer 1

$1250/ounce x 1 ounce/31.1 g = $40.19/gram

How many grams can you buy with 2 pennies?

$0.02 x 1 gram/$40.19 = 0.0004976 grams 

How many atoms of gold is this?

4.976x10^-4 g x 1 mole gold/197 g x 6.02x10²³ atoms/mole = 1.52x10¹⁸ atoms of gold