2.8 Time in Decimal Form
How much time is 3.25 h in hours and minutes?
When we calculate time in decimal form, we need to think closely.
3.25 h is NOT the same thing as 2 hours and 25 minutes. Why?
In the picture to the right, we can clearly see that 0.25 h = 15 minutes. So 3.25 h = 3 hours and 15 minutes. The reason for this is that there is 60 minutes in 1 hour.
How do we then think when we work with time in decimal form?
Let’s look at a few more examples:
Example 1
How do you express 2 hours and 18 minutes in decimal form?
18 min = 
18
60 
h = 0.3 h 
2 hours and 18 minutes = 2.3 h
Example 2
How do you write 4.6 h in hours and minutes?
4.6 h = 4 hours and (0.6 · 60) min = 4 hours and 36 min
4.6 h = 4 hours and 36 minutes
