How many significant figures are in the following number?
3.40 X 10-6

(2.68 x 10^22 atoms) x (238 g U / 6.022 x 10^23 atoms) = 10.59 g of U.

The number least significant figures in the multiplication and division problem is 3 significant figures (2.68). So, following significant figure rules for multiplication, your answer should have 3 significant figures.

The final answer is: 10.6 g U

Explanation:

Hopefully this helps :)