Hello there!
We would practically divide both 16 and 3.We would want to find out how many 3's go into 16.
Let's see.
3+
3=6+
3=9+
3=12+
3=15
There are five 3's.
This would help us and understand that 5 is our main big number.
We have 1 left. We would divide this by 3, and your result would be
. . . 
I hope this helps you!