Time
🧩 Let’s Start with a Problem
Sam is planning his school day.
His art lesson starts at $10:15$ a.m. and finishes at $11:00$ a.m.
He wants to know how long the lesson lasts, but he sees the time written in different ways on different clocks.
🔍 Think About It
How can Sam use hours and minutes to work out the time between $10:15$ a.m. and $11:00$ a.m.?
💡 Why This Matters
Time helps us plan, compare, and describe events during the day.
We use time when we follow a timetable, arrive on time, measure how long activities take, and read both analogue and digital clocks.
⚡ Quick Warm-Up
Activity $1$: Count the minutes.
A break starts at $9:30$ a.m. and ends at $9:45$ a.m. How many minutes does the break last?
Think about it: Count forward from the start time to the finish time.
Activity $2$: Match the time words.
Which digital time matches “quarter past $8$ in the morning”: $8:15$ a.m. or $8:45$ a.m.?
Think about it: “Quarter past” means $15$ minutes after the hour.
Activity $3$: Think about morning and afternoon.
A football club meets at $4:20$ in the afternoon. Should this time be written with a.m. or p.m.?
Think about it: Times after midday and before midnight use p.m.
➡️ Ready to Learn
Now let’s learn how to read, write, and compare time using analogue clocks, digital clocks, a.m., p.m., and the $24$-hour clock.
🎯 In this topic you will
- Read and tell the time using both digital and analogue clocks.
- Use a.m. and p.m. correctly when telling the time.
- Understand and use both 12-hour and 24-hour clock notation with digital and analogue clocks.
🧠 Key Words
- a.m.
- analogue clock
- digital clock
- hour
- minute
- p.m.
- second
Show Definitions
- a.m.: The part of the day from midnight to midday, used when telling time.
- analogue clock: A clock that shows time using moving hands on a numbered clock face.
- digital clock: A clock that shows the time using numbers, usually on a screen.
- hour: A unit of time equal to 60 minutes.
- minute: A unit of time equal to 60 seconds.
- p.m.: The part of the day from midday to midnight, used when telling time.
- second: The smallest common unit of time, used to measure very short durations.
🕒 Two Time Scales on an Analogue Clock
A n analogue clock has two number scales. One scale shows the hours from midnight to midday, and the other shows the hours from midday to midnight. This helps us tell whether the time is in the morning or the afternoon.
⏱️ Reading Time on a Digital Clock
A digital clock can show time using the 24-hour system. For example, a time of 13:26 means 1:26 in the afternoon, which is written as 1.26 p.m. in the 12-hour clock system.
❓ EXERCISES
1. Copy and complete the following:
a. There are _____ days in September.
b. There are _____ minutes in $1$ hour.
c. There are _____ months in a year.
d. There are _____ seconds in $1$ minute.
👀 Show answer
a. $30$
b. $60$
c. $12$
d. $60$
2. Write the missing numbers.
a. $3$ minutes $=$ _____ seconds
b. $5$ hours $30$ minutes $=$ _____ minutes
c. $7$ weeks $=$ _____ days
d. _____ months $=$ $3$ years
e. _____ hours $=$ $2$ days $6$ hours
f. _____ minutes $=$ $7 \tfrac{1}{2}$ hours
g. $300$ seconds $=$ _____ minutes
👀 Show answer
a. $180$
b. $330$
c. $49$
d. $36$
e. $54$
f. $450$
g. $5$
3. Ali went swimming at $5.15$ p.m. Which clock shows the time Ali went swimming?
👀 Show answer
Clock C
4. Copy and complete the table to show the time using a.m. and p.m.
👀 Show answer
Quarter past seven in the morning: $7.15$ a.m.
Quarter to ten at night: $9.45$ p.m.
Twenty minutes past three in the afternoon: $3.20$ p.m.
5. Petra looks at the clock in the classroom. She says, “It is almost lunchtime.” Write the time using a.m. or p.m.
👀 Show answer
$11.45$ a.m.
6. Chen goes swimming at ten past five in the afternoon. Which digital clock shows when Chen goes swimming?
👀 Show answer
$17:10$
7. A wall clock shows this time.
Which two digital clocks could show the same time as the wall clock?
👀 Show answer
$12:00$ and $18:00$
8. Ava converts $9$ p.m. to a $24$-hour clock time. Her answer is $19.00$. Ava’s answer is wrong. Correct Ava’s answer. Explain what she did wrong.
👀 Show answer
The correct answer is $21.00$.
Ava added $10$ instead of $12$ when converting from p.m. to the $24$-hour clock.
🧠 Think like a Mathematician
Digital clocks
Milly dropped her digital clock. When she picked it up she could not tell which way up it was.
a) Write in words the two different ways of saying what the time is.
b) Write three other times that look the same on a digital clock whichever way up it is.
Use these digital numbers to help you:
1 2 3 4 5 6 7 8 9 0
You will show you are specialising when you find times that look the same on a digital clock whichever way it is up.
👀 show answer
a) The time can be read as one ten (1:10). When the clock is upside down, it can also be read as ten past one in the opposite orientation.
b) Examples of other times that look the same whichever way up the clock is:
- 2:50 (uses only digits that still form valid digits when turned upside down)
- 5:20
- 8:08
These times work because the digits 0, 1, 2, 5, 8 still look like valid digits when rotated 180°, and their order remains meaningful.
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