Answer :
The answer is 3,680. There are three zeroes in 1,000 therefore you need to move the decimal point over to the right three places.
1 0 0 0
x 3 . 6 8
------------------
8 0 0 0
6 0 0 0
+ 3 0 0 0
-------------------------
3 6 8 0 . 0 0 = 3, 680
x 3 . 6 8
------------------
8 0 0 0
6 0 0 0
+ 3 0 0 0
-------------------------
3 6 8 0 . 0 0 = 3, 680