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.