Lesson 8 of 10 · Chapter 8
The Delivery Driver
You drive for Express Delivery. In this lesson you find how much time passes between two clock times, work out end times and latest start times, plan a whole delivery route, and convert between hours, minutes and seconds, so every package arrives on time.
Choose how you want to learn
You can change this any time. Press Listen on any part to hear it read aloud. Grown-ups: read along with younger children.
- 1 · Clock intervals
- 2 · Elapsed time
- 3 · End times and deadlines
- 4 · Planning a route
- 5 · Converting time
- 6 · The whole chapter
- 7 · Try it at home
- 8 · Your card
- 9 · Check yourself
Part 1
Time intervals on the clock
60 minutes make 1 hour. 60 seconds make 1 minute.
To find the minutes between two times in the same hour, subtract the minutes: 9:20 to 9:45 is 45 − 20 = 25 minutes.
To add minutes, count up to the next full hour first.
45 minutes after 10:30 AM: 30 minutes takes you to 11:00, and 15 more makes 11:15 AM.
On a clock face, the long hand counts minutes. Each number on the dial is 5 minutes, so from the 4 to the 9 is 5 numbers, or 25 minutes.
Watch for noon: the hour after 11 AM is 12 PM, then 1 PM.
“Minutes and Hours: 60 minutes = 1 hour”
“Seconds and Minutes: 60 seconds = 1 minute”
Read the clocks and answer. Five right to finish.
Part 2
Elapsed time: count in chunks
Elapsed time is how much time passes between a start and an end.
Count in chunks: up to the next full hour, then whole hours, then the minutes left.
10:45 AM to 2:20 PM: 10:45 to 11:00 is 15 minutes. 11:00 AM to 2:00 PM is 3 hours. 2:00 to 2:20 is 20 minutes. Total: 3 hours 35 minutes.
The timeline shows the same trip: each mark is a full hour you can count.
Drivers log elapsed time for every route, because it is how they get paid and how dispatchers plan the next day.
“Method: Count in chunks”
“Total: 3 hours 35 minutes”
How long between the two times? Type hours and minutes, like 3 hr 35 min. Five right to finish.
Part 3
End times and deadlines
To find an end time, add the hours first, then the minutes.
To find the latest start, work backward from the deadline.
Start 2:45 PM, lasting 2 hours 35 minutes: 2:45 + 2 hours = 4:45 PM, then + 35 minutes = 5:20 PM.
A package must arrive by 3:00 PM and the trip takes 45 minutes: 3:00 PM − 45 minutes = 2:15 PM. Leave any later and it arrives late.
“End time: 5:20 PM”
“Leave by: 2:15 PM at latest”
Find the end time or the latest start. Five right to finish.
Part 4
Planning a delivery route
A route is a list of stops. Multiply stops × minutes per stop to get the total time.
Change big numbers of minutes into hours and minutes, then add to the start time.
5 deliveries × 25 minutes = 125 minutes. 125 ÷ 60 = 2 remainder 5, so 2 hours 5 minutes. Start at 9:00 AM and you finish at 11:05 AM.
Real routes add up stops of different lengths: 45 + 30 + 60 + 25 + 40 = 200 minutes, or 3 hours 20 minutes.
“5 deliveries × 25 minutes each = 125 minutes”
“Start 9:00 AM → Finish 11:05 AM”
Plan the route and find when you finish. Three right to finish.
Part 5
Converting time
Minutes to hours: divide by 60. The remainder is the minutes left over.
Hours to minutes: multiply by 60.
185 minutes: 185 ÷ 60 = 3 remainder 5, so 3 hours 5 minutes.
2 hours 45 minutes: 2 × 60 = 120, plus 45 = 165 minutes.
Decimal hours are common on time sheets: 3.5 hours is 3 hours and half an hour, which is 210 minutes. 1.75 hours is 105 minutes.
“Divide by 60: 185 ÷ 60 = 3 remainder 5”
“120 + 45 = 165 minutes”
Convert the time. Five right to finish.
Part 6
Read the whole chapter
Here is all of Chapter 8, “The Delivery Driver”, exactly as the book tells it, with every worked example, all 56 practice problems and the Action Report. Press Listen to hear it read aloud, or open it and work along with a pencil.
Open Chapter 8
Part 7
Try it at home
Do these with your family. Tick each one when it is done.
Part 8
Your “Delivery Driver” card
Fill it in, then print it for the fridge. Nothing you type here leaves this device.
Delivery Driver’s Card
Global Sovereign University · Grade 4 Mathematics, lesson 8
Time rules
- 60 seconds = 1 minute; 60 minutes = 1 hour.
- Count in chunks: to the hour, whole hours, minutes left.
- End time: add hours, then minutes. Latest start: work backward.
- Minutes ÷ 60 = hours, remainder = minutes.
Part 9
Check yourself
6 questions. Pick an answer. If it is not right, read the hint and try again.
Lesson 8 complete.
You can find time intervals and elapsed time, work out end times and latest starts, plan a delivery route, and convert between hours, minutes and seconds. Next: Lesson 9, The Garden Designer. Back to the class.
Homeschooling Math Books for Kids: Grade 4 by Dr. Gene A Constant. This lesson is Chapter 8, and the whole chapter is on this page.
GSU is a 501(c)(3) nonprofit and book sales are its only income. A purchase is not a tax-deductible donation. This lesson is free and always will be.