It seems that to find the number of hours and minutes between 2 given time can prove to be a little challenging.
There are namely two ways to go about it, using subtraction or counting onwards. Subtraction may seem straight forward but would require some adjustments to the way subtraction is done normally. This would apply to cases where renaming is required; when borrowing from the hours to the minutes, renaming would be 60 (since 1 hour equates to 60 minutes). Below is an example:
The number of hours and minutes between 8:50am and 11:10am is ? When we try to subtract 50 minutes from 10 minutes, we are not able to since 10 is smaller than 50. Therefore, we need to borrow from the hour. When this is done, 10 minutes now become 70 minutes and the result is 20 minutes. The hour part now becomes 10 - 8 = 2 hours. The final result is 2 hours 20 minutes.
A structured way to approach this would be as follows:
8:50am ----------- 9:50am ------------- 10:50am ----------------- 11:00am ------------------11:10am
1hr 2hr 2hr10min 2hr20min