Time

Grade 5 · Mathematics

Semester 2 | Period 4 | Week 19

Download the Lessonotes Mobile Liberia app for faster lesson access on Android and iPhone.

Get it on Google Play Get it on the Apple App Store

Subject: Mathematics

Semester: 2

Period: 4

Week: 19

School Name:
Teacher’s Name:
Subject: Mathematics
Grade Level: Grade 5
Date: Week 19
Lesson Duration: 45 minutes
Week & Period: Week 19, Period 4
Topic: Time
Sub-topic: Finding Elapsed Time
Learning Objectives
By the end of the lesson, students should be able to:

  1. Recall how to read time in hours, minutes, and seconds.
  2. Calculate elapsed time by subtracting the start time from the end time.
  3. Solve real-life problems involving elapsed time.

Previous Knowledge
Students already know how to read both digital and analog clocks.

Instructional Materials
Mathematics textbook for Grade 5, toy clocks, wall clock, timeline charts, worksheets

Lesson Development – ABC Model
A – Anticipation (Warm-up / Starter)
Time: 5–10 minutes
Teacher asks students to recall the current time and then predict what the time will be after 30 minutes. Students also share daily routines (wake-up time, school time) to connect with elapsed time.

B – Building Knowledge (Main Lesson Body)

Time: 25–30 minutes

Definition (Fully Explained):

Elapsed Time is the total amount of time that has passed between a starting time and an ending time. It is used to determine how long an event, task, or activity lasted.

Formula:

Elapsed Time=End Time−Start Time

Elapsed time can be measured in hours, minutes, or seconds, and it is important in daily life (schedules, timetables, appointments, etc.).

Methods for Finding Elapsed Time:

  1. Timeline Method:
    Count forward in steps using a timeline. Start at the beginning time, and move forward hour by hour and then minute by minute.
  2. Subtraction Method:
    Convert both start and end times into minutes, subtract, then convert back to hours and minutes.

 

Examples (Expanded):

Example 1:
Start Time: 8:00 a.m.
End Time: 2:00 p.m.
Elapsed Time: 6 hours

Example 2:
Start Time: 10:15 a.m.
End Time: 12:45 p.m.
Step-by-Step (Timeline):

  • From 10:15 to 12:15 = 2 hours
  • From 12:15 to 12:45 = 30 minutes
    Total: 2 hours 30 minutes

Example 3:
Start Time: 3:50 p.m.
End Time: 6:20 p.m.
Method:

  • From 3:50 to 4:00 = 10 minutes
  • From 4:00 to 6:00 = 2 hours
  • From 6:00 to 6:20 = 20 minutes
    Total Elapsed Time: 2 hours 30 minutes

Example 4 (Subtraction Method):
Start Time: 9:35
End Time: 11:05
Convert both to minutes:

  • 9:35 = (9 × 60) + 35 = 575 minutes
  • 11:05 = (11 × 60) + 5 = 665 minutes
    Elapsed Time = 665 – 575 = 90 minutes = 1 hour 30 minutes

 

Learners’ Activities (Expanded):

  • 🔹 Toy Clock Activities:
    Students set toy clocks to the start and end times given by the teacher and physically move the hands to count how much time has passed.
  • 🔹 Draw Timelines:
    Students draw horizontal timelines and label them with times. They count hours and minutes forward to find the elapsed time.
  • 🔹 Group Work – Journey Problems:
    In small groups, learners solve elapsed time problems such as:
    • A flight that leaves at 9:20 a.m. and arrives at 12:10 p.m.
    • A TV show that starts at 5:45 p.m. and ends at 6:30 p.m.
  • 🔹 Daily Routine Timetables:
    Students use their own daily routines (e.g., from waking up to arriving at school) to calculate elapsed time.
  • 🔹 Class Timetable Activity:
    Learners identify periods between school subjects (e.g., English from 8:00 to 8:45, break from 10:30 to 10:50) and find elapsed times.

 

Assessment Checks (Expanded):

  • ✅ Quick Oral Questions:
    • “If you start homework at 4:10 p.m. and finish at 5:25 p.m., how long did you spend?”
    • “How much time passes between 1:45 p.m. and 3:15 p.m.?”
  • ✅ Written Exercise:
    Students are given 5 start and end times to calculate elapsed time using both timeline and subtraction methods.
  • ✅ Application Tasks:
    • "The school bus leaves at 7:30 a.m. and arrives at school at 8:20 a.m. How long is the journey?"
    • "Lunch starts at 12:30 p.m. and ends at 1:10 p.m. What is the duration of lunch break?"
  • ✅ Challenge Question:
    • "A movie started at 6:40 p.m. and ended at 8:15 p.m. It had a 15-minute break halfway. How long was the movie excluding the break?"

 

Notes (Expanded & Detailed):

  • ⏰ Key Concepts:
    Elapsed time is crucial for scheduling, managing time, and understanding real-life timelines.
  • 📌 Common Errors to Watch For:
    • Forgetting to convert minutes properly
    • Mixing up AM and PM
    • Not regrouping when minutes in end time are smaller than start time (borrow 1 hour = 60 minutes)
  • 📖 Helpful Strategies:
    • Always break the time down into parts (hours first, then minutes)
    • Use number lines or timelines for visual learners
    • Encourage learners to check by counting forward and backward

C – Consolidation (Conclusion & Assessment)
Time: 5–10 minutes
Summary: Elapsed time is the total amount of time passed between two points. We can calculate it by subtracting start time from end time or by using a timeline.

Evaluation Method (Expanded):
Exit slip/quiz: Students solve one elapsed time problem (e.g., A movie starts at 4:25 p.m. and ends at 6:05 p.m. How long is the movie?). Teacher will collect slips and provide oral feedback.
Assignment (Expanded): Students record their bedtime and wake-up time for two days and calculate the elapsed sleeping time.
Follow-up Activity: Practice solving timetable-related problems.
Differentiation / Inclusive Strategies
Pair struggling learners with peers for support. Use visual aids like toy clocks and timelines for learners with difficulties.
Teacher’s Reflection (After Class)
What worked well? ___________________________________________
What needs improvement? ____________________________________
Students’ engagement level: ☑ High ☑ Medium ☑ Low