All the solutions provided in McGraw Hill My Math Grade 3 Answer Key PDF Chapter 11 Lesson 6 Time Intervals will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 3 Answer Key Chapter 11 Lesson 6 Time Intervals
To determine a time interval, find the amount of time that passes from the start of an activity to the end of an activity.
Math in My World
Example 1
Evan’s mother put biscuits in the oven at 5:10 P.M. She took them out of the oven at 5:27 P.M. HOW much time passed from the time she put the biscuits in the oven to the time she took them out?
Find the time interval from 5:10 to 5:27.
1. Find the start time. The start time is ____________ P.M.
2. Find the end time. The end time is ______________ P.M.
3. Count by 5s from 5:10 to 5:25.
4. Count on by ones from 5:25 to 5:27.
So, _____________ minutes passed from 5:10 P.M. to 5:27 P.M.
The time interval was ____________ minutes.
Answer:
The start time is 5:10 P.M.
The end time is 5:27 P.M.
The count by 5s from 5:10 to 5:25 is 15 mins
Count by 1s from 5:25 to 5:27 is 2 mins
15 + 2 = 17 mins
So, 17 minutes passed from 5:10 P.M. to 5:27 P.M.
The time interval was 17 minutes.
Example 2
The clock shows the time June’s choir practice ended ¡n the afternoon. If it was 135 minutes long, what time did it start?
Count back 135 minutes from 3:15 P.M. Use the number line.
The time interval for choir practice was _____________ minutes, or ____________ hours and ___________ minutes.
135 minutes before 3:15 P.M. is _____________ P.M.
Choir practice started at ______________ P.M.
Answer:
3 hour 15 mins – 135 mins
1 hour = 60 mins
135 mins = 2 hour 15 mins
3 hour 15 mins – 2 hour 15 mins = 1 hour
Choir practice started at 1 P.M.
Talk Math
Lupe took a nap at the time shown and woke up at 1:30 P.M. Explain how you can find how long he slept.
Answer:
Lupe took a nap at the time shown and woke up at 1:30 P.M.
1:30 – 12:15 = 1 hour 15 mins
Thus he slept for 1 hour 15 mins.
Guided Practice
Question 1.
Find the time interval of a movie. Use the number line.
____________ minutes + _____________ minutes = _____________ minutes, or
__________ hour and ____________ minutes.
Answer:
60 minutes + 30 minutes = 90 minutes or 1 hour and 30 minutes
So, the time interval is 1 hour 30 minutes
Independent Practice
The following are times of baseball games. Find the time interval for each.
Question 2.
Start Time (P.M.) End Time (P.M.)
Answer:
60 minutes + 45 minutes + 7 minutes = 112 minutes
So, the time interval is 112 minutes or 1 hour 52 minutes
Question 3.
_____________ minutes
Answer:
The start time is 12:15 p.m.
The end time is 2:28 pm.
2:28 – 12:15 = 2 hour 13 minutes
So, the time interval is 2 hour 13 minutes
Question 4.
_____________ minutes
Answer:
The start time is 1:20 p.m.
The end time is 5:05 p.m.
5:05 – 1:20
4 hour 65 min
-1 hour 20 minute
3 hour 45 min
So, the time interval is 3 hour 45 minutes
Write the time. Then draw the hands on the clock to show the time interval.
Question 5.
Answer:
The start time is 11:55 a.m.
35 minutes earlier is 11:55 – 35 min = 11:20
Question 6.
Answer:
The start time is 10:30 p.m.
36 minutes earlier is 10 hour 30 min + 36 min = 10 hour 66 min = 11:06 p.m.
Problem Solving
Question 7.
Tyrone started mowing lawns at 1:10 P.M. He finished mowing at 4:05 P.M. HOW much time did Tyrone spend mowing lawns?
Answer:
Given,
Tyrone started mowing lawns at 1:10 P.M.
He finished mowing at 4:05 P.M.
4 hour 5 min
-1 hour 10 min
2 hour 55 min
Thus Tyrone spends 2 hour 55 mins mowing lawns.
Question 8.
It takes Louisa one hour and 30 minutes to get to her aunt’s house. She leaves at 4:00 P.M. Draw the hands on the clock to show the time she will get to her aunt’s house. Then write the time.
Answer:
Given,
It takes Louisa one hour and 30 minutes to get to her aunt’s house. She leaves at 4:00 P.M.
4 hour + 1 hour 30 mins = 5 hour 30 mins
HOT Problems
Question 9.
Mathematical PRACTICE Reason How do the units of time, such as minutes and hours, relate to each other?
Answer:
The relationship between minutes and hours are
1 hour = 60 minutes
Question 10.
Mathematical PRACTICE Which One Doesn’t Belong? Circle the set of digital clocks that does not show a time interval of 85 minutes. Explain.
Answer:
Set B and C does not belong to the time interval of 85 minutes.
Question 11.
Building on the Essential Question How can I determine the duration of time intervals in hours?
Answer: The time interval is the difference between the two given points in the time.
McGraw Hill My Math Grade 3 Chapter 11 Lesson 6 My Homework Answer Key
Practice
The following are times of parades. Find the time interval for each.
Question 1.
Answer:
60 minutes + 60 minutes + 18 minutes = 138 minutes
Question 2.
____________ minutes
Answer:
The start time is 2:15 p.m.
The end time is 4:05 p.m.
The time interval is 3 hour 65 min – 2 hour 15 mins = 1 hour 50 mins
Question 3.
_____________ minutes
Answer:
The start time is 9:00 a.m.
The end time is 11:37 a.m.
The time interval is 2 hour 37 minutes
Write the time. Then draw the hands on the clock to show the time interval.
Question 4.
Answer:
The starting time is 4:45 P.M.
50 minutes earlier is 3:55 P.M.
Question 5.
Answer:
The time is 9:10 A.M.
27 minutes later is 9:37 A.M.
Problem Solving
Question 6.
It took Henry 2 hours and 17 minutes to write his report. He started writing at 3:30 P.M. What time did he finish his report?
Answer:
Given,
It took Henry 2 hours and 17 minutes to write his report. He started writing at 3:30 P.M.
3 hour 30 min
+2 hour 17 min
5 hour 47 min
Thus he finishes his report at 5:17 P.M.
Question 7.
Mathematical PRACTICE Plan Your Solution Melanie started working in her garden at 8:25 A.M. She took a break at 11:10 A.M. How many minutes did Melanie work before taking a break?
Answer:
Given,
Melanie started working in her garden at 8:25 A.M. She took a break at 11:10 A.M.
11 hour 10 minutes – 8 hour 25 minutes
10 hour 70 minutes
-8 hour 25 minutes
2 hour 45 minutes
Melanie work 2 hour 45 mins before taking a break.
Vocabulary Check
Question 8.
Write a definition for a time interval.
Answer:
The definition of a time interval is a length of time can be divided into a number of shorter periods of time, all of the same length.
Test Practice
Question 9.
It takes Wallace 50 minutes to do the grocery shopping. If he starts at 2:12 P.M. what time will he finish?
(A) 2:42 P.M.
(B) 2:52 P.M.
(C) 3:02 P.M.
(D) 3:07 P.M.
Answer:
Given,
It takes Wallace 50 minutes to do the grocery shopping.
he starts at 2:12 P.M.
2 hour 12 minutes + 50 minutes = 2 hour 62 minutes
60 minutes = 1 hour
2 hour 62 minutes = 3 hour 2 minutes = 3:02 p.m.
Thus option C is the correct answer.