Question

Explain how finding 4x384 can help you find 4x5384

Answer 1

You break down the equation 

4x5000=20,000
4x300=1,200
4x80=320
4x4=16

then you add those numbers all up.

20,000
  1,200
     320
+     16
------------
21,536

you can do the same with finding:
4x384
4x5000