Example

1. Regroup to subtract Example
	  11:30
	-  8:45
	_________
         
	
	_________

Step 1 - Rewrite

8:45
9:00
10:00
11:00
11:45

Step 2 - See how much to add in each step

8:45
9:00	-- 15 min (since 8:45)
10:00   -- 1 hour (since 9:00)
11:00  	-- 1 hour (since 10:00)
11:45	-- 45 minutes (since 11:00)

Step 3 - Add hours

1 hour + 1 hour = 2 hours

Step 4 - Add minutes

15 min + 45 minutes = 60 minute

Step 5 - make minutes into hours if they are more than 60

60 minutes = 1 hour 0 minutes

Step 6 - Add all together

2 hours + 1 hour + 0 minutes = 3 hours and 0 minutes