Lesson 8: Time - 1

For Grade 5 Students (Ages 10-11) - Let's learn to tell and manage time!

What we will learn today:

In this lesson, you will learn to:

  • Read and write time using analog and digital clocks.
  • Understand the concepts of AM and PM.
  • Convert between hours and minutes.
  • Solve simple word problems involving time.

Introduction to Time

Hello, young mathematicians! Time is a very important part of our daily lives. We use time to know when to wake up, when to go to school, when to play, and when to sleep.

Understanding time helps us plan our day and be punctual. Today, we will learn how to read time from different types of clocks and understand how time is measured.

Do you know how many minutes are in an hour? Or how many hours are in a day? Let's find out!

Reading Time: Analog Clock

An **analog clock** has two main hands:

  • The **short hand** is the **hour hand**. It points to the hour.
  • The **long hand** is the **minute hand**. It points to the minutes.
Each number on the clock face represents 5 minutes for the minute hand.

Example 1: Reading Analog Clock

If the hour hand is pointing to $3$ and the minute hand is pointing to $12$, the time is **$3$ o'clock**.

If the hour hand is just past $7$ and the minute hand is pointing to $6$, the time is **$7:30$** (seven thirty or half past seven).

Exercise 1: Write the time shown on the analog clock (assume standard clock faces).

Hour hand at 9, Minute hand at 12.

Hour hand between 2 and 3, Minute hand at 6.

Hour hand just past 11, Minute hand at 3.

Hour hand between 4 and 5, Minute hand at 9.

Reading Time: Digital Clock

A **digital clock** shows time using numbers, usually separated by a colon (:). The numbers on the left show the hours, and the numbers on the right show the minutes.

Example: $08:35$ means 8 hours and 35 minutes.

Digital clocks often use the 24-hour format or specify AM/PM.

Understanding AM and PM

A day has 24 hours. To avoid confusion between morning and evening times, we use **AM** and **PM**.

  • **AM** stands for "ante meridiem," which means **before noon**. It covers time from midnight ($12:00$ AM) to just before noon ($12:00$ PM).
  • **PM** stands for "post meridiem," which means **after noon**. It covers time from noon ($12:00$ PM) to just before midnight ($12:00$ AM).

Examples:

  • $7:00$ AM is seven in the morning (when you wake up).
  • $7:00$ PM is seven in the evening (when you might have dinner).
  • $12:00$ PM is Noon.
  • $12:00$ AM is Midnight.

Converting Time: Hours and Minutes

We know that:

  • $1$ hour = $60$ minutes
  • $1$ minute = $60$ seconds

Example 3: Convert $2$ hours to minutes.

Since $1$ hour = $60$ minutes, then $2$ hours = $2 \times 60 = 120$ minutes.

Example 4: Convert $90$ minutes to hours and minutes.

We know $60$ minutes make $1$ hour. So, $90$ minutes = $60$ minutes + $30$ minutes = $1$ hour and $30$ minutes.

Exercise 2: Convert hours to minutes.

$3$ hours = $\underline{\hspace{2cm}}$ minutes

$5$ hours = $\underline{\hspace{2cm}}$ minutes

$10$ hours = $\underline{\hspace{2cm}}$ minutes

Exercise 3: Convert minutes to hours and minutes.

$75$ minutes = $\underline{\hspace{1cm}}$ hour $\underline{\hspace{1cm}}$ minutes

$130$ minutes = $\underline{\hspace{1cm}}$ hours $\underline{\hspace{1cm}}$ minutes

$200$ minutes = $\underline{\hspace{1cm}}$ hours $\underline{\hspace{1cm}}$ minutes

Problem Solving with Time

Let's apply what we've learned to solve some real-life problems involving time.

Exercise 4: Solve the following word problems.

  1. A movie started at $3:00$ PM and ended at $5:00$ PM. How long was the movie?

  2. You started studying at $6:30$ PM and finished at $7:15$ PM. How many minutes did you study?

  3. If a train journey takes $3$ hours and $20$ minutes, how many minutes is the journey in total?

Answers to Practice Time

Let's check your answers!

  1. Exercise 1: Reading Analog Clock

    • 1. $9:00$
    • 2. $2:30$
    • 3. $11:15$
    • 4. $4:45$

  2. Exercise 2: Convert hours to minutes

    • $3$ hours = $180$ minutes
    • $5$ hours = $300$ minutes
    • $10$ hours = $600$ minutes

  3. Exercise 3: Convert minutes to hours and minutes

    • $75$ minutes = $1$ hour $15$ minutes
    • $130$ minutes = $2$ hours $10$ minutes
    • $200$ minutes = $3$ hours $20$ minutes

  4. Exercise 4: Problem Solving with Time

    • The movie was $2$ hours long.
    • You studied for $45$ minutes.
    • The journey is $200$ minutes in total.

You've completed Lesson 8!

Excellent work, Math Lanka students! You've successfully learned to read time, understand AM/PM, and convert between units of time. Keep practicing, and you'll always be on time!

Next Lesson
Previous Lesson Next Lesson