Arithmetic Grade Six

Lesson Thirty-three: Adding Hours and Minutes

Sometimes the answer in the minutes column winds up to be greater than 59. In this case we must regroup. Take a look at this problem and answer: 


	  3:40
	+ 3:40
	------
	  6:80
This answer is unacceptable. We must regroup.

We know that 80 minutes is equal to 1 hour and 20 minutes and so we can regroup and get an answer like this: 


	  3:40
	+ 3:40
	------
	  7:20
Here's another example: 

	  4:45
	+ 3:25
	-------
	  8:10
Since 45 and 25 add up to 70 we must regroup. We can get one hour with ten leftover minutes out of 70 and so we add one to our hour's column and leave the leftover minutes in the minute's column.

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