Elapsed time | 4th grade Math Worksheet | GreatSchools - Free Printable

I'll solve the elapsed time problems in this worksheet step by step.

First, let me examine the image to understand what's being asked.

Looking at the worksheet, I can see it's about calculating elapsed time with several problems:

1. Reading times from analog clocks and calculating the difference
2. Calculating how long a lunch break is based on start and end times
3. Calculating how long someone worked based on start and end times
4. Calculating when a program ends based on start time and duration
5. Calculating the earliest time someone could start painting based on work hours and required time

Let me solve each problem one by one.

Problem 1: Clocks
The clocks show:
- First clock: 10:45
- Second clock: 11:45 (1 hour later)
- Third clock: 12:40 (55 minutes after 11:45)
- Fourth clock: 1:27 (47 minutes after 12:40)

The question asks for the elapsed time between 10:45 and 1:27.
From 10:45 to 1:45 would be 3 hours, but we need to go to 1:27, which is 18 minutes less than 1:45.
So, 3 hours minus 18 minutes = 2 hours and 42 minutes.

Wait, let me recalculate more carefully:
From 10:45 to 11:45 = 1 hour
From 11:45 to 12:45 = 1 hour (but we only go to 12:40, so that's 55 minutes)
From 12:40 to 1:27 = 47 minutes
Total: 1 hour + 55 minutes + 47 minutes = 1 hour + 102 minutes = 2 hours 42 minutes.

Actually, let me do this differently:
From 10:45 to 1:27
Hours: 10 to 1 = 2 hours (since 1 PM is 13:00, 13-10=3, but we're going from 10:45 to 1:27, so it's less than 3 hours)
Better to calculate total minutes:
From 10:45 to 1:27 is 2 hours and 42 minutes (since 10:45 + 2 hours = 12:45, then 12:45 + 42 minutes = 1:27).

Problem 2: Lunch break
Starts at 12:00 AM, ends at 1:15 AM
That's 1 hour and 15 minutes.

Problem 3: Work time
Starts at 6:25 AM, ends at 5:17 PM
From 6:25 AM to 5:25 PM would be 11 hours, but we end at 5:17 PM, which is 8 minutes earlier.
So, 11 hours minus 8 minutes = 10 hours and 52 minutes.

Problem 4: TV Program
Starts at 9:30 AM, lasts 8 hours
9:30 AM + 8 hours = 5:30 PM

Problem 5: Painting job
Must work 15 hours, starts at 11:30 AM, works 1 hour 45 minutes per day.
First, let's calculate how many days are needed: 15 hours ÷ 1 hour 45 minutes per day.
1 hour 45 minutes = 1.75 hours
15 ÷ 1.75 = 8.57 days, so 9 days are needed (since you can't work a fraction of a day in this context).

If they start on Day 1 at 11:30 AM, after 8 full days they would have worked 8 × 1.75 = 14 hours.
They need 1 more hour on Day 9.
So they start on Day 9 at 11:30 AM and work 1 hour, finishing at 12:30 PM.

But the question asks for the earliest time they could start painting the same day. Since they must work 15 hours total and can only work 1 hour 45 minutes per day, they can't finish in one day. The earliest they could start is still 11:30 AM, but they won't finish that day.

Actually, re-reading the question: "What is the earliest time she could start painting the same day?" This seems to be asking for the earliest start time on any day, which would be 11:30 AM as given.

Let me double-check all my calculations.

Actually, I think I misunderstood Problem 5. Let me re-read it:
"Mrs. Reddell must paint a room that requires 15 hours to complete. She can only work 1 hour 45 minutes per day. What is the earliest time she could start painting the same day?"

This is asking for the earliest time she could start on a given day, which is simply 11:30 AM as stated in the problem. The 15 hours and 1 hour 45 minutes per day information might be there to distract or for a different interpretation, but the question specifically asks for the earliest time she could start painting the same day, which is 11:30 AM.

Let me now provide the final answers for each problem:

1. Elapsed time from 10:45 to 1:27 is 2 hours and 42 minutes.
2. Lunch break is 1 hour and 15 minutes.
3. Work time from 6:25 AM to 5:17 PM is 10 hours and 52 minutes.
4. TV program ends at 5:30 PM.
5. Earliest time to start painting is 11:30 AM.

I believe these are the correct solutions to the problems presented in the worksheet.