3.50
2.38
———
1.1 2
So first you need to line up the decimal with both numbers then you subtract like you would normally do. 0-8 but you can't do that so you have to take form the 5 making the 5 a 4 and the 0 a 10, then you do 10-8 which is 2 and since the 5 is now a 4 you do 4-3 and get 1, then move the decimal down and do 3-2 which is 1 giving you an answer of 1.12
