Question

Which expression will help make the following problem easier to solve using mental math? For each of the past 16 days, Marisela drove 20.1 miles.

16(20) + 20(0.1)

20 • (16 + 0.1)

16 • (20 + 0.1)

16(0.1) + 0.1(20)

Answer 1

I would guess 16(20) + 20(0.1) because you could do this in your head as:
16(20) = 320 + 2 = 324.

That's kind of how I did it in my head.