Here is the map of this whole chapter, and it is worth memorising as a picture: grams ⇄ moles ⇄ particles. Grams cross to moles through $M$; moles cross to particles through $N_A$. There is no direct road from grams to particles — none — so every such question is a two-step, and moles are the hinge every chemistry chain swings on.

Going right you divide by $M$, then multiply by $N_A$. Coming back you divide by $N_A$, then multiply by $M$. Write hop one's answer down before starting hop two: a chain question grades the CHAIN, and a slip in the first line walks all the way to the last. And keep the magnitude habit alive — if your particle count comes back looking like an ordinary number, you divided where you should have multiplied.