Skill: Solve elapsed time problems

Elapsed time is how long it takes to get from a starting time to an ending time. Use a clock or timeline and count forward, combining hours and minutes.

Example: A movie starts at 2:45 p.m. and ends at 4:10 p.m. How long is the movie?

1. Count from 2:45 to 3:00:
   $(15)$ minutes.

2. Count from 3:00 to 4:00:
   $1$ hour.

3. Count from 4:00 to 4:10:
   $(10)$ minutes.

4. Combine the parts:

$$15\text{ minutes}+1\text{ hour}+10\text{ minutes} =1\text{ hour }25\text{ minutes}$$

The movie lasts 1 hour 25 minutes.

Remember: Minutes are counted in groups of $(60)$, not $(100)$. A timeline helps you cross an hour correctly.