Time
🎯 In this topic you will
- Read and record time using analogue clocks.
- Read and record time using digital clocks.
- Link analogue times with their digital equivalents.
🧠 Key Words
- analogue clock
- digital clock
- minute
Show Definitions
- analogue clock: A clock that shows time using moving hands on a numbered face.
- digital clock: A clock that shows time using numbers on a screen instead of hands.
- minute: A unit of time equal to one sixtieth of an hour, used to measure short periods of time.
⏰ Why Time Matters
M easuring time is part of everyone’s life. Knowing the time can be useful when we need to catch a bus or a train. It helps us get to school on time and lets us know when it is time to leave school.
❓ EXERCISES
$1.$ On each of these clocks the minute hand is missing. Working with a partner, estimate the time by finding where the minute hand should be.
👀 Show answer
Answers will vary slightly. Use the position of the hour hand to estimate where the minute hand should be (on $12$ for o’clock, near $6$ for half past, near $9$ for quarter to, etc.).
$2.$ Write the time shown on these clocks. The first one is done for you.
a. $03{:}15$ (quarter past $3$)
b. $03{:}13$
c. $09{:}27$
d. $01{:}52$
e. $04{:}17$
f. $08{:}34$
👀 Show answer
a. Quarter past $3$.
b. $3{:}13$ (thirteen minutes past $3$).
c. $9{:}27$ (twenty-seven minutes past $9$).
d. $1{:}52$ (eight minutes to $2$).
e. $4{:}17$ (seventeen minutes past $4$).
f. $8{:}34$ (twenty-six minutes to $9$).
$3.$ Match the digital time to the analogue time that is shown on the clock.
👀 Show answer
Match each digital display to the clock face by comparing hour and minute positions (e.g. $04{:}17$, $12{:}48$, $13{:}45$).
$4.$ Choose three of your favourite times of day. Show each time on an analogue clock and on a digital clock. For each time, write what activity you are doing. What time will it be after $1$ hour and $10$ minutes for each of your times?
👀 Show answer
Answers depend on the times chosen. Add $1$ hour and $10$ minutes to each selected time (for example, $07{:}30 \rightarrow 08{:}40$).
$5.$ Write the times shown on these clocks.
👀 Show answer
Read each clock by finding the hour hand first, then counting the minutes in groups of $5$ from $12$.
🧠 Think like a Mathematician
This digital stopwatch is broken.
a. Every time it is switched on only five light bars work. What different numbers could it show?
b. Investigate for other numbers of light bars. Is there a number of light bars that matches the number shown on the display? How many different numbers can you find that do that?
👀 show answer
- a. On a seven-segment display, exactly five light bars are used to make the digits $2$, $3$, and $5$. So the stopwatch could show $2$, $3$, or $5$.
- b. Trying other numbers of light bars:
• $2$ bars → $1$
• $3$ bars → $7$
• $4$ bars → $4$
• $5$ bars → $2,\,3,\,5$
• $6$ bars → $0,\,6,\,9$
• $7$ bars → $8$
The only case where the number of bars equals the digit shown is $4$ (it uses four bars). So there is exactly one such number.