An aluminum cylinder in a physics lab had a mass of 29.7 grams. How many aluminum atoms are present in this cylinder?

Question

___________ × 1023 Al atoms. Do NOT enter the unit and report your final answer with 3 SFs.

Answer 1

a mol, Avogadro's number , of Al atoms has mass of 26.98 grams
so
(29.7 / 26.98) 6.023 * 10^23

Answer 2

So i plugged into that calculator and got 6.630211268e23
Is that sound about right?

Answer 3

yes, but 3 SF you said
6.63 * 10^23