We included **HMH Into Math Grade 3 Answer Key PDF** **Module 12 Lesson 5 Solve Time Interval Problems **to make students experts in learning maths.

## HMH Into Math Grade 3 Module 12 Lesson 5 Answer Key Solve Time Interval Problems

I Can use a number line to find the end time or the start time when I know two amounts of elapsed time.

**Step It Out**

Question 1.

The third grade class will visit a museum that opens at 10:00 a.m. It takes 45 minutes to travel from the school to the museum. The students need 12 minutes to get on the bus. At what time should the students start boarding the bus to be sure they arrive at the museum when it opens?

A. Use a number line. Find 10:00 a.m. Count back _________ minutes to find the time that the bus needs to leave the school.

Think: You can break apart the minutes into shorter amounts of time.

Answer:

B. Count back ________ minutes to find the time the students need to board on the bus.

Answer:

Count back 57 minutes to find the time the students need to board on the bus.

C. At what time should the students start boarding the bus?

Answer:

At 9:03 the students start boarding the bus

**Turn and Talk** How can you use the start time and jump forward to check the reasonableness of your answer?

Answer:

The students start at 9: 03 and reach at museum by 10:00

Question 2.

Miley wants to see the dinosaur animation show, it takes 10 minutes to get from the entrance of the museum to the show. There is a wait time of 15 minutes at the entrance to the show. The show lasts 20 minutes. If Miley arrives at the museum at 4:00 p.m., at what time does Miley finish watching the show?

A. Write an equation to find the total number of minutes from the time Miley gets to the museum to the time she finishes watching the show.

Answer:

Let the elapsed time be n

n = 10 + 15 + 20

n = 45

elapsed time = 45 minutes

end time = start time + elapsed time

x = 4:00 + 0:45

x = 4 : 45

B. Count forward on the number line the total number of minutes from the time Miley arrives at 4:00 Pm- the museum.

Answer:

elapsed time = 45 minutes

end time = start time + elapsed time

x = 4:00 + 0:45

x = 4 : 45

C. Miley will finish watching the show at ________.

Answer:

elapsed time = 45 minutes

end time = start time + elapsed time

x = 4:00 + 0:45

x = 4 : 45

Miley will finish watching the show at 4:45 p.m.

**Turn and Talk** Do you need to add the times in the same order they were given in the problem? Explain.

Answer:

no, we don’t need to add the times in the same order they were given in the problem.

we have to add the total time.

**Check Understanding**

Question 1.

A concert starts at 7:00 p.m. The chorus performs for 30 minutes. There is a 15-minute break and then the band performs for 30 minutes. Use the number line to find the time the concert ends.

Answer:

concert ends at 8:15 p.m.

Explanation:

The chorus performs for 30 minutes.

There is a 15-minute break and then the band performs for 30 minutes.

30 + 30 + 15 = 75 minutes

that is 1 hour 15 minutes

7:00 + 1 :15 = 8:15

**On Your Own**

**Attend to Precision** Write the start time or end time. Use a.m. or p.m.

Question 2.

Start at 4:34 p.m.

4 minutes to bicycle to the park

15 minutes playing at the park

3 minutes to bicycle home

End at ___________

Answer:

End at 4:56 .m.

Explanation:

Elapsed time = 4 + 15 + 3 = 22 minutes.

4 : 34 + 0:22 = 4:56 p.m.

Question 3.

Start at ___________

24 minutes to mow the lawn

18 minutes to weed the garden

12 minutes to trim the hedges

End at 10:00 a.m.

Answer:

start at 9 : 06 a.m.

Explanation:

Elapsed time = 24 + 18 + 12 = 54

to find the start time

we have to subtract the 54 minutes from start time

10 : 00 – 0 : 54 = 9 : 06

Question 4.

**STEM** Greg is 32 years old. He has a resting heart rate of 65 beats per minute. Greg measures his heart rate after jogging. He stops jogging at 8:46 a.m. At first, Greg’s heart rate is 155 beats per minute. The table shows his heart rate after each different amount of time passes. At what time, after Greg stops jogging, is his heart rate at 78 beats per minute?

Answer:

8:52 a. m.

Explanation:

He stops jogging at 8:46 a.m. At first, Greg’s heart rate is 155 beats per minute.. Then after 6 minutes, his heart became to 78 beats per minute.

So 8:46 a.m.+ 6 min = 8:52 a.m.

Question 5.

**Reason** Al wants pizza for lunch. It takes 15 minutes to make the pizza, 18 minutes for it to cook, and 3 minutes to cool. What time should Ai make the pizza if he wants to eat at 11:55 a.m.? Explain.

Answer:

At 11 : 19 Ali started making the pizza

Explanation:

15 minutes to make the pizza,

18 minutes for it to cook, and

3 minutes to cool

15 + 18 + 3 = 36

11 : 55 – 0 : 36 = 11 : 19 a.m.

Question 6.

**Use Tools** Chorus practice starts with 10 minutes of warm-ups. Then the singers practice a song for 40 minutes. The clock shows the end time of practice for the song. At what time does chorus practice start? Describe how you found the time.

Answer:

chorus practice start at 1 : 4

Explanation:

Chorus practice starts with 10 minutes of warm-ups.

Then the singers practice a song for 40 minutes.

40 + 10 = 50

start time = 2 : 30

2 : 30 – 0 : 50 = 1 : 40

Question 7.

**Social Studies** The Library of Congress in Washington, D.C., is the largest library in the world. Malachi arrives at the library at 11:00 a.m. He spends 17 minutes at an exhibit of Thomas Jefferson’s books. Then he spends 24 minutes at an Exploration of Americas exhibit and 19 minutes at a current exhibit before a guided tour of the library. At what time does Malachi’s guided tour begin?

Answer:

10 : 00a.m. Malachi’s guided tour begin

Explanation:

17 minutes at an exhibit of Thomas Jefferson’s books.

24 minutes at an Exploration of Americas

19 minutes at a current exhibit

17 + 24 + 19 = 60

11 : 00 – 0 : 60 = 10 : 00a.m.

Question 8.

**Reason** Sami arrives at school at 8:02 a.m. It takes her 6 minutes to get to class. She has reading for 45 minutes and then science for 38 minutes. Can you add the times in any order to tell what time science ends? Explain.

Answer:

yes, we can add in any order

Explanation:

It takes her 6 minutes to get to class.

She has reading for 45 minutes and

then science for 38 minutes.

45 + 38 + 6 = 89

89 minutes is 1 hour 29 minutes

8 : 02 – 1 : 29 = 9 : 31 science ends