All the solutions provided in McGraw Hill My Math Grade 4 Answer Key PDF Chapter 11 Lesson 7 Convert Units of Time will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 4 Answer Key Chapter 11 Lesson 7 Convert Units of Time
The steps that you use to convert units of length, weight, and capacity can be used to convert units of time.
Math in My World
Example 1
Cooper watched a butterfly in his garden for 5 minutes. How many seconds did he watch the butterfly?
1 minute = 60 seconds
To convert larger units of time to smaller units of time, multiply.
5 × 60 = _____________
So, Cooper watched a butterfly for ____________ seconds.
Answer:
5 × 60 = 300
So, Cooper watched a butterfly for 300 seconds.
Example 2
Audrey is going to watch a movie at the movie theater. The movie starts at 3:30 P.M. and ends at 5:37 P.M. How long is the movie in minutes?
Find the time interval, or the length of time from the start of the movie to the end of the movie.
The time interval between 3:30 and 5:37 is ________________ hours and 7 minutes. ← Count the whole hours. From 3:30 to 5:30 is 2 hours. Count the remaining minutes. From 5:30 to 5:37 is 7 minutes.
Since 1 hour = 60 minutes, multiply 60 by 2.
60 × 2 = _______________ 120 + 7 = _______________
So, the movie is _______________ minutes long.
Answer:
Find the time interval, or the length of time from the start of the movie to the end of the movie.
The time interval between 3:30 and 5:37 is 2 hours and 7 minutes. ← Count the whole hours. From 3:30 to 5:30 is 2 hours. Count the remaining minutes. From 5:30 to 5:37 is 7 minutes.
Since 1 hour = 60 minutes, multiply 60 by 2.
60 × 2 = 120, 120 + 7 = 127
So, the movie is 127 minutes long.
Talk Math
What operation would you use to find the number of minutes in 2 hours? Explain.
Answer:
To convert larger units of time (hours) to smaller units of time(minutes), multiply.
Therefore, we would use to multiplication to find the number of minutes in 2 hours.
Guided Practice
Complete each conversion table.
Question 1
Answer:
1 min equal 60 sec.
2 mins will be 2×60 = 120 sec.
3 mins will be 3×60 = 180 sec.
4 mins will be 4×60 = 240 sec.
Question 2.
Answer:
1 day equals 24 hrs.
2 days will be equal to 2×24 = 48 weeks.
3 days will be equal to 3×24 = 72 weeks.
4 days will be equal to 4×24 = 96 weeks.
Question 3.
Answer:
1 year equals 52 weeks.
2 weeks will be equal to 2×52 = 104 weeks.
3 week will be equal to 3×52 = 156 weeks.
4 week will be equal to 4×52 = 208 weeks.
Independent Practice
Complete each conversion table.
Question 4.
Answer:
1 week equals 7 days.
2 weeks will be equal to 2×7 = 14 days.
4 weeks will be equal to 4×7 = 28 days.
6 weeks will be equal to 6×7 = 42 days.
8 weeks will be equal to 8×7 = 56 days.
Question 5.
Answer:
1 hour will be 60 mins.
3 hours will be equal to 3×60 = 180 mins.
4 hours will be equal to 4×60 = 240 mins.
5 hours will be equal to 5×60 = 300 mins.
6 hours will be equal to 6×60 = 360 mins.
Question 6.
Answer:
1 year will be equal to 12 months.
3 years will be equal to 3×12 = 36 months.
5 years will be equal to 5×12 = 60 months.
7 years will be equal to 7×12 = 84 months.
Question 7.
Answer:
1 year equals to 52 weeks.
5 years will be equal to 5×52 = 260
10 years will be equal to 10×52 = 520
15 years will be equal to 15×52 = 780
20 years will be equal to 20×52 = 1040
Compare. Use <, >, or =.
Question 8.
5 min 
250 s
Answer:
Conversion of min to sec.
1 min equals to 60 sec.
5 min will be 5×60 = 300 s
Thus, 300 > 250
Question 9.
36 mo 4 y
Answer:
Conversion of year to mo.
1 year equals to 12 mo.
4 y equals to 4 × 12 = 48 mo.
Thus, 36 < 48
Question 10.
300 s 1 h
Answer:
Conversion of h to s.
1 h equals 360 s.
Thus, 300 < 360
Question 11.
How many times greater is one minute than one second?
Answer:
1 minute equals to 60 seconds.
Therefore, 1 minute is 60 times greater than one second.
Question 12.
How many times greater is one hour than one minute?
Answer:
1 hour equals to 60 minutes.
Therefore, 1 hour is 60 times greater than one minute.
Question 13.
How many times greater is one week than one day?
Answer:
1 week equals 7 days.
Therefore, one week is 7 times greater than one day.
Question 14.
How many minutes are in the time interval from 1:22 P.M. to 5:44 P.M.?
Answer:
The time interval between 1:22 and 5:44 is 4 hours and 22 minutes. ← Count the whole hours. From 1:22 to 5:44 is 4 hours. Count the remaining minutes. From 1:22 to 5:44 is 22 minutes.
Since 1 hour = 60 minutes, multiply 60 by 4.
60 × 4 = 240, 240 + 22 = 262
There are 262 minutes in 1:22 P.M. to 5:44 P.M.
Question 15.
How many minutes are in the time interval from 7:09 A.M. to 10:36 A.M.?
Answer:
The time interval between 7:09 and 10:36 is 3 hours and 27 minutes. ← Count the whole hours. From 7:09 to 10:36 is 3 hours. Count the remaining minutes. From 7:09 to 10:36 is 27 minutes.
Since 1 hour = 60 minutes, multiply 60 by 3.
60 × 3 = 180, 180 + 27 = 207
There are 207 minutes in 7:09 A.M. to 10:36 A.M.
Problem Solving
Question 16.
Aubrey played on the playground for 2\(\frac{1}{2}\) hours. How many minutes did she play?
Answer:
Given that: Aubrey played on the playground for 2\(\frac{1}{2}\) hours.
1) Convert the whole hours
Since 1 hour = 60 minutes, multiply 60 by 2.
2 × 60 = 120 minutes.
2) Convert the fractions
\(\frac{1}{2}\) of 60 minutes equals 30 minutes.
3) Add the parts
120 + 30 = 150 mins.
Thus, Aubrey played for 150 mins.
Question 17.
Alex had to rent the pavilion at the park for a minimum of 3 hours. How many minutes is that?
Answer:
Given that: Alex had to rent the pavilion at the park for a minimum of 3 hours.
Since 1 hour = 60 minutes, multiply 60 by 3.
60 × 3 = 180 mins
Alex had to rent the pavilion at the park for a minimum of 180 mins.
Question 18.
Mathematical PRACTICE Use Math Tools Justin painted his fence from 8:00 A.M. to 11:47 A.M. For how many minutes did he paint the fence?
Answer:
Given that: Justin painted his fence from 8:00 A.M. to 11:47 A.M.
The time interval between 8:00 and 11:47 is 3 hours and 47 minutes. ← Count the whole hours. From 8:00 to11:47 is 3 hours. Count the remaining minutes. From 8:00 to11:47 is 47 minutes.
Since 1 hour = 60 minutes, multiply 60 by 3.
60 × 3 = 180, 180 + 47 = 262
There are 262 minutes in 1:22 P.M. to 5:44 P.M.
Question 19.
It took Aiden 20 minutes to walk to school. It took Callie 900 seconds to walk to school. Who took less time to walk to school?
Answer:
Given that: Aiden took 20 minutes and Callie took 900 seconds to walk to school.
Since 1 minute equals to 60 seconds.
20 minutes will be equal, 200 × 60 = 12000 sec
As 12,000 > 900. Callie took less time to walk to school.
HOT Problems
Question 20.
Mathematical PRACTICE Find the Error Sadie wrote the following on the board. Find and correct her mistake.
2 years = 24 weeks
Answer:
1 year equals to 12 months or 52 weeks.
Sadie multiplied the number of years by 12 instead of 52.
There are 2×12=24 months or 2×52=104 weeks in 2 years.
Question 21.
Building on the Essential Question How does multiplication relate to time conversions?
Answer:
Multiplication is done to convert the larger units of time to smaller units of time.
For example, to convert 5 hours to minutes. We multiply by 60 as 1 hours equals to 60 mins.
Thus, 5 hours in minutes will be 5×60 = 300 mins.
McGraw Hill My Math Grade 4 Chapter 11 Lesson 7 My Homework Answer Key
Practice
Convert units to complete each equation.
Question 1.
3 minutes = ________________ seconds
Answer:
Since 1 minute = 60 seconds, multiply 60 by 3.
60 × 3 = 180
3 minutes = 180 seconds
Question 2.
5 weeks = ________________ days
Answer:
Since 1 week = 7 days, multiply 7 by 5.
7 × 5 = 35
5 weeks = 35 days
Question 3.
_________________ months = 5 years
Answer:
Since 1 year = 12 months, multiply 12 by 5.
12 × 5 = 60
60 months = 5 years
Question 4.
________________ minutes = 6 hours
Answer:
Since 1 hour = 60 minutes, multiply 60 by 6.
60 × 6 = 360
360 minutes = 6 hours
Question 5.
4 days = _________________ hours
Answer:
Since 1 day = 24 hours, multiply 24 by 4
24 × 4 = 96
4 days = 96 hours
Question 6.
__________________ weeks = 8 years
Answer:
1 year equals 52 weeks.
8 years will be 8×52 = 416
416 weeks = 8 years
Question 7.
1\(\frac{1}{2}\) days = ________________ hours
Answer:
1) Convert the whole days
1 day = 24 hrs
2) Convert the fractions
\(\frac{1}{2}\) of 24 hours equals 12 hours.
3) Add the parts
24 + 12 = 36 hours.
1\(\frac{1}{2}\) days = 36 hours.
Question 8.
3\(\frac{2}{7}\) weeks = _________________ days
Answer:
1) Convert the whole weeks
Since 1 week = 7 days, 3 × 7 = 21 days.
2) Convert the fractions
\(\frac{2}{7}\) of 7 days equals 2 days.
3) Add the parts
21 + 2 = 23 days
3\(\frac{2}{7}\) weeks = 23 days.
Question 9.
_______________ months = 4\(\frac{3}{4}\) years
Answer:
1) Convert the whole years
Since 1 year = 12 months, 4 × 12 = 48 months.
2) Convert the fractions
\(\frac{3}{4}\) of 12 months equals 9 months.
3) Add the parts
48 + 9 = 57 months
57 months = 4\(\frac{3}{4}\) years
Question 10.
_________________ minutes = 6 hours and 42 minutes
Answer:
Since 1 hour equal 60 minutes, multiply 60 by 6.
60 × 6 = 360
360 + 42 = 402 minutes
402 minutes = 6 hours and 42 minutes
Complete each conversion table.
Question 11.
Answer:
1 week equals to 7 days.
2 weeks will be equal to 2×7 = 14 days.
4 weeks will be equal to 4×7 = 28 days.
6 weeks will be equal to 6×7 = 42 days.
8 weeks will be equal to 8×7 = 56 days.
Question 12.
Answer:
1 hour equals 60 mins.
9 hours will be equal to 9×60 = 540 mins.
7 hours will be equal to 6×60 = 360 mins.
5 hours will be equal to 5×60 = 300 mins.
3 hours will be equal to 3×60 = 180 mins.
Problem Solving
Question 13.
Emma is 9\(\frac{1}{4}\) years old. How many months old is Emma?
Answer:
Given that: Emma is 9\(\frac{1}{4}\) years old.
Since 1 hour equal 60 minutes, multiply 60 by 9.
60×9 = 540
Emma is 540 months old.
Question 14.
Mathematical PRACTICE Model Math Vincent is watching a movie that lasts 1 hour and 37 minutes. He has watched 52 minutes so far. How many minutes are left in the movie?
Answer:
Given that: Vincent is watching a movie that lasts 1 hour and 37 minutes. He has watched 52 minutes so far.
1 hour equals 60 minutes.
60 + 37 = 97 mins.
1 hour 37 minutes equals to 97 mins
He has watched 52 minutes so far. So the left over minutes in the movie will be 97-52 = 45 mins
Question 15.
Lexie started her homework at 4:30 P.M. She finished at 5:05 P.M. How many seconds did it take her to finish her homework?
Answer:
Given that: Lexie started her homework at 4:30 P.M. She finished at 5:05 P.M.
The time interval between 4:30 and 5:05 is 1 hour and 25 minutes. ← Count the whole hours. From 4:30 to 5:05 is 1 hour. Count the remaining minutes. From 4:30 to 5:05 is 25 minutes.
Since 1 hour = 60 minutes.
60 + 45 = 105 mins
Since 1 min equals 60 seconds.
105 × 60 = 6300 seconds
There are 6300 seconds to finish her homework.
Vocabulary Check
Question 16.
How many seconds are in 1 minute?
Answer:
There are 60 seconds in a minute.
Test Practice
Question 17.
Cameron’s book log shows that he read a total of 4\(\frac{1}{4}\) hours last month. How many minutes is that?
(A) 240 minutes
(B) 250 minutes
(C) 255 minutes
(D) 270 minutes
Answer:
Given that: Cameron’s book log shows that he read a total of 4\(\frac{1}{4}\) hours last month.
1) Convert the whole hour
1 hour = 60 mins, so 4 hours will be 4×60 = 240 mins.
2) Convert the fractions
\(\frac{1}{4}\) of 60 mins equals 15 mins.
3) Add the parts
240 + 15 = 255 mins.
4\(\frac{1}{4}\) hours = 255 mins.
Therefore, option C is correct.