A Lesson on Elapsed Time

Primary Type: Lesson Plan
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 73378
Wow! Where Has the Time Gone? A Lesson on Elapsed
The lesson is designed to help students with the concept of elapsed time through the use of T-charts and number lines. Students will be able to tell
and write time to the nearest time interval in minutes, and solve word problems involving addition and subtraction of time intervals in minutes using
situational word problems.
Subject(s): Mathematics
Grade Level(s): 3
Intended Audience: Educators
Suggested Technology: Document Camera,
Computer for Presenter, Internet Connection, LCD
Instructional Time: 3 Hour(s)
Resource supports reading in content area: Yes
Freely Available: Yes
Keywords: Elapsed time
Resource Collection: FCR-STEMLearn Mathematics General
Doc1 Line Sample Word.docx
Doc1 Tchart Sample 1 Word.docx
Doc2 Number Line Sample 2 Word.docx
Math Rubric Scale Word.docx
Tchart Sample 2 Word.docx
Guided Practice Questions.docx
T chart Elapsed Time worksheet.pdf
Summative Evaluation.docx
Formative Assessment for Elapsed Time4.docx
Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
Students will be able to tell and write time to the nearest time interval in minutes, and solve word problems involving addition and subtraction of time intervals in
Prior Knowledge: What prior knowledge should students have for this lesson?
Students should know the intervals of time:
Quarter hour
Half hour
page 1 of 5 Students should know the necessary vocabulary:
analog clock
Digital clock
Time interval
Elapsed time
T chart
Students should have already been introduced to Standard MAFS.2.MD.3.7 Measurement and Data and working with time
Guiding Questions: What are the guiding questions for this lesson?
How did you arrive at your answer?
What were you thinking while you were solving the problem?
What did you need to know to answer the question?
Is it possible to say the same time two different ways?
What could you do differently?
Is there a step that you missed?
How do you know that the elapsed time is ______?
What strategy did you use to figure that out?
Can you model that strategy? •Is your answer reasonable?
Why it is important to know how much time has passed?
How can we use elapsed time in our daily lives?
Teaching Phase: How will the teacher present the concept or skill to students?
1. First, the teacher will hook the students by showing a video on You Tube introducing how to use a T-chart while solving elapsed time. You will need to remove any
ads before showing this to students. http://www.youtube.com/watch?v=5bu14OfrbLE
2. Then, ask and discuss real world questions such as:
What time does school end?
What time do you go to bed?
What time does your favorite T.V. show come on?
What time does it end?
Why do we need to learn about elapsed time?
How can we use elapsed time aspects in our daily lives?
Is it possible to say the same time two different ways?
What happens when you don't arrive on time?
What time do you eat breakfast?
The vocabulary needed for the lesson will be reviewed, and the teacher will spend a few minutes practicing telling time. Review the standard and objective for the day
and discuss the rubric for the lesson. Students will use the rubric to self assess prior to the lesson.
Elapse Time Rubic Word.docx
3. The formative assessment will be given. Formative Assessment for Elapsed Time.docx Allow about ten minutes for the students to respond to the question. Walk
around the class and encourage students when help is needed, but do not help them arrive at an answer.
4. After ten minutes, have a class discussion on how students solved the problem and what the correct answer is.
5. The teacher will tell the students that today's lesson will be on computing elapsed time using a T-chart. 5.
6. As a hook, the teacher will then show the quick video, which is located in the attachments. After the video, the students will observe the teacher modeling the use
of the T-chart to solve the Summative question.
7. The teacher will model another example of elapsed time using the T chart in solving a situational word problem.
8. The teacher will write this problem on the dry erase board, chalkboard, or on a piece of paper on the LCD projector: Ms. Webster went shopping at the
Altamonte Mall. She started shopping at 10:30 and finished at 2:48. How much time did she spend shopping at the mall?
9. Pull out the T-chart. Write starting time on the top left of the chart.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
1. The teacher will model another example of elapsed time using the T chart in solving a situational word problem. Write this problem on the dry erase board,
chalkboard, or on a piece of paper on the LCD projector. "Ms. Webster went shopping at the Altamonte Mall. She started shopping at 10:30 a.m."
2. Students can use theT-chart, provided in the attachment section, or create their own T-charts using a dry erase board, or on a piece of paper. Tell students to
write starting time on the top left of the chart, banking time on the right, and ending time at the bottom right. Start working down the chart. (A sample for the
teacher is provided in the attachment section.) On the left side write, 10:30-11:30, on the right side bank one hour. Then write, 11:30 -12:30 on the left side and
on the right side, bank two hours.
3. Next, on the left side, you will write 12:30-1:30 and the right side bank three hours. Continue to write the hours working down, which will be 1:30-2:30, banking the
fourth hour.
4. Ask the students, "Will we bank any additional hours?" "If not, why?" The students may respond, "No, because you will go over the time frame. The next hour would
be from 2:30 -3:30 and Miss Webster left the mall at 2:48." The teacher should respond by asking what friendly or compatible numbers we could now use. The
students should respond by intervals of 5 minutes, or ten minutes, and either could be used. Ask which interval would be more efficient and quicker, and the
students should respond by an interval of ten minutes. The four banked hours ended at 2:30.
5. Work your way toward the ending time of 2:48 by intervals of ten on the right side, banking those minutes. 2:30 to 2:40 is ten minutes.
page 2 of 5 6. Ask, "Can we use another ten minute interval to bank?" "If not, why?" A response may be, "That would take you to 2: 50 and she stopped shopping at 2:48." The
teacher then asks, "What time intervals should we now use?" The response should be minutes. Going back to the T chart, you have four hours and ten minutes
banked ending at 2:40.
7. Bank the minutes on the right side of the chart by writing 2:41, bank one minute, 2:42, bank two minutes, 2:43, bank three minutes, 2:44, bank four minutes, 2:45,
bank five minutes, 2:46 bank, six minutes, 2:47 bank seven minutes, 2:48, bank eight minutes. Miss Webster stopped shopping at 2:48, so we don't need to
continue because that is the ending time.
8. Now, add up the banked time. Four hours + ten minutes + 8 minutes= Four hours and eighteen minutes. Answer the question in a complete sentence. "Miss
Webster spent four hours and eighteen minutes shopping at the Altamonte Mall."
9. Using the guided practice sheet provided in the attachment section, the teacher will guide the class while solving the two problems. The teacher will continue to
model the use of the T-chart while eliciting responses and engaging in class discussion throughout the process. The students will follow along while working with
their right shoulder partner, as they write on the T-chart the individual, sequential steps that the teacher will be guiding them through. The individual steps in the
problem solving process, along with the teacher's guidance, will help the students to process how to arrive at elapsed time while using a T-chart.
10. Continue to check student progress and monitor student understanding. Clarify any misunderstandings and misconceptions. Assign Independent practice worksheet,
even numbers only for homework. The site is the Mathworksheets4 kids, located in the Independent work section.
Day 2
1. Review standard, objective, and rubric with the class.
2. Ask if anyone would like to summarize what they learned on Day 1 of the lesson.
3. Ask if anyone would like to come up front and solve a problem from the independent homework sheet, located in the Independent Practice section. Make sure that
the student explains their thinking process and to justify and defend their answers. Call on two, or three students to do two, or three, problems from the homework.
4. Ask if any students had questions, problems, or misconceptions while using the T-chart. Call on two students to share what they had written in their reflective
5. Check the rest of the independent practice homework from day 1. Students will keep these sheet for Day two's homework assignment, solving the odd numbers
using a number line.
6. Say, "Today we are going to extend our elapsed time knowledge by using a different strategy while solving the same situational problem that we did yesterday as
our formative assessment. Today we will be using a timeline instead of a T-chart to determine elapsed time. Please look over your timeline that I have placed on
your desk."
http://illuminations.nctm.org/Lesson.aspx?id=3966 (Pick the timeline with the most timeline intervals.)
7. Ask, "Why would we use a number timeline to help us?" Have a quick discussion on strategies. Say, "Let's go back to yesterday's Formative Assessment. We are
going to solve the exact same problem today using a timeline."
8. Re-read the Formative Assessment. "Melissa and Candido started soccer practice at 5:45 pm and the session ended at 7:36 pm. How much time
elapsed between the start of practice and the end of practice?" "Watch me as I use a time number line to find the answer." Use this document as a
reference: Doc1 Numbler Line Sample 1 Word.docx
9. Ask, "What time where we should start?" Wait for the response, 5:45 p.m. When it is given, say, "I'll mark the starting time on the timeline." Ask, "What time
should we finish?" "I will mark the finishing time on the timeline as well?"
10. Tell the students that they are going to count the minutes between the starting and finishing time for soccer practice.
11. For guided practice, continue using the Illustrations number line to do the following two problems with the class. Use the elapsed time number line to determine the
answers to the following word problem.
Guided Problem #1.) Sara had to baby sit the Clark children. She arrived at their house at 5:19 p.m. and left their house at 11:36 p.m. How long did she babysit the
Clark children? Doc2 Number Line Sample 2 Word.docx
"Let's get started on the elapsed time number line."
Say, "Okay, what time do we start with? That's right!" "5:19"
Ask, "What is the most efficient, or largest time interval that we should start with in this equation?" "Hours." "Why?" ".... Because it is the largest time interval on
the timeline that we can use."
Let's arch our hours as we count off. "What is our finishing time? 11:26" Let's use our humpty humps and count off the hours and mark our time line. Mark your
number line with me. 5:19-6:19 = 1 hour, 6:19-7:19, 2 hours, 7:19-8:19, 3 hours, 8:19-9:19, 4 hours. 9:19 -10:19, 5 hours, 10:19 -11:19, 6 hours." Make sure
that the students are marking the times on their number time line.
Ask, "Can we go further using hour intervals? No, why?"
Ask, "What is the largest interval should we use now?" Students should respond, "Ten minutes."
Ask, "Where do we start using ten minute intervals?" "Where we left off at 11:19?" "Yes."
"Now, what was her ending time?" "11:36." "Let's start counting at 11:19 and marking our timeline by every ten minutes."
11:19-11:29 = ten minutes. "Can we go another ten minutes? No." "Why?" "Students should respond because it would be 11:39 and she left at 11:36."
Okay, now let's start counting by five minutes. 11:29-11:30 = 1 minute/11:30-11:31=2 minutes/11:31-11:32 = 3 minutes/11:32-11:33 = 4 minutes/11:33-11:34=5
page 3 of 5 minutes/11:35-11:36 =6 minutes. "Could you count in ten minute intervals? How would you do that?" (Point out other ways to get this time. You could add a minute,
then 5, then 1. Can anyone think of another way to count these minutes?
Now, let's add up the time. 6 hours + 10 minutes+6 minutes= 6 hours and 16 minutes.
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the
Day 1: The students will start on elapsed-time-minute-Independent practice #1 worksheet http://www.mathworksheets4kids.com/time/elapsed time/elapsed-timeminutes-medium1.pdf and do the even problems for homework. The students will continue to use their T-charts as a tool, or math aide, which will help them to
develop the concept of elapsed time. Through modeling and guided practice, along with independent practice, the students will develop conceptual understanding and
fluency. At the end of the lesson, have students write a summary about using T-charts to tell elapsed time in their reflective math journals.
Day 2: The students will work on elapsed-time-minutes- Independent practice #1 http://www.mathworksheets4kids.com/time/elapsed time/elapsed-time-minutesmedium1.pdf Day 1 and do the odd problems for homework using an elapsed number timeline. Students will also be asked to write a summary about using a number
timeline to help tell elapsed time in their reflective journals.
Day 3: Review concepts and strategies. Ask the students if they see a connection between the T-chart strategy and the time number line strategy. Ask the students if
they preferred one strategy, or the other, and which one they thought was the easiest. Give the Summative Assessment. Summative Evaluation.docx
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
1. The teacher will ask the students to discuss with a partner or in a small group what they did during the lesson, what strategies they used, and what they may still
be struggling with.
2. The teacher will provide chart paper for each group to write their summaries on. A few minutes will be given for each group to share their information.
3. The teacher will re-state and clarify as students share.
4. Afterwards, each student will summarize and record what they learned in their math notebook or journal.
Summative Assessment
Summative Evaluation.docx The Summative assessment strategy will be an exit slip with three questions moving towards rigor. The students will be required to solve
the questions and defend their answers. Students will also be required to explain the strategy they used, as well as, self assess using the Elapsed time rubric. Elapse
Time Rubic Word.docx
Formative Assessment
Students will be given a real world problem dealing with how much time elapsed during a soccer practice session. Pass out the formative assessment worksheet, or
put on a LCD Projector, or the write problem on a dry erase, or chalkboard. Formative Assessment for Elapsed Time.docx. After allowing a few minutes for students to
complete the problem, students will use Math Rubric Scale to gauge their current level of understanding.
Math Rubric Scale.docx
Feedback to Students
1. Ask students if they would like to share their answers and strategies they used to solve them. The teacher will respond to the students' answers and suggest
possible ways for students to self-correct. For example, if a student does not understand elapsed time and responds by guessing, even though he/she can read a
clock, the teacher may realize that the student is not applying that knowledge to elapsed time. The teacher may have the student become accountable for his/her
time in class. You can say that they have ten minutes before science class, set a timer and stick to it. The student could also hold the job of being the class time
keeper to ensure that the class keeps its daily schedule and arrives punctually to wherever they are scheduled to be, whether it's lunch, specials, or to a
2. The teacher will also provide two to three examples that he/she noticed when walking around the classroom during student work time to share with the class.
The teacher will ask a student with a correct example to explain how he/she arrived at that answer. If the student is having a difficult time explaining their
answer, the teacher will help the child verbalize their answer and provide clarification as needed. The teacher will ask the student what they were thinking and if
they have an idea of what they would have done differently. The teacher should ask the class if there were any other ways of arriving at the solution and if so, to
demonstrate them.
3. The teacher will meet one on one with any student that had difficulty with the elapsed time concept in order to improve student performance. The teacher will ask
guiding questions that will help the individual student to move towards self direction, self correction, and efficiency.
Allow students to draw visual representations that will help with the thinking and procedural processes.
Provide Judy Clocks, which they can manipulate manually.
Have students create their own daily timeliness.
Have students do only three independent problems in class and three for homework. (Provide do-able, workable chunks.)
Have students sit close to the teacher and select an average ability student to be their right shoulder partner.
Read word problems to the students when doing independent work. Circle data and underline questions so that the student understands what the problem is asking
them to do.
Time Interactive Clock activity from www.owego.org/ocsd-web/games/BangOnTime
Students can create a T.V. schedule of programs.
Students can create a "Jeopardy-like" elapsed time game.
Students can create an elapsed time bingo game.
Students can read, A Long Wait by Annie Cobb.
Students can research examples of real-world applications on elapsed time.
Students can plan a field trip or a vacation trip with their family.
page 4 of 5 Students can create their own situational elapsed time problems. Exchange with another high ability student to solve.
Students can create a class schedule, or a train, or bus schedule, and ask elapsed time questions.
Have students to write a story using elapsed time situations in their narratives.
Suggested Technology: Document Camera, Computer for Presenter, Internet Connection, LCD Projector
Special Materials Needed:
Timeline number line ruler
Dry Erase board, erasers, and markers
Guided and Independent Worksheets
Reflection Journals
Computer LCD projector
Teacher work samples T-chart 1 & 2
Teacher work samples timeline number line 1 & 2
Formative and Summative Tests
Further Recommendations:
Have a family night on elapsed time. Use ideas from the Elapsed time, NSA Gov. Word document.
Free homework extensions could be found based on level of difficulty on: www.mathworksheets4kids.com
Additional Information/Instructions
By Author/Submitter
This lesson supports the following Standards for Mathematical Practice:
MAFS.K12.MP.1.1-Make sense of problems and persevere in solving them.
MAFS.K12.MP.4.1- Model with mathematics.
Contributed by: Ruth Gail Webster
Name of Author/Source: Ruth Gail Webster
District/Organization of Contributor(s): Orange
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Tell and write time to the nearest minute and measure time intervals in minutes. Solve word problems involving addition
and subtraction of time intervals in minutes, e.g., by representing the problem on a number line diagram.
page 5 of 5