Time
🎯 In this topic you will
- Choose appropriate units of time for different activities.
- Understand and use time intervals.
🧠 Key Words
- time
- time interval
Show Definitions
- time: A measure of how long something lasts, often recorded using units such as seconds, minutes, or hours.
- time interval: The amount of time between two moments (for example, from a start time to an end time).
⏳ Time Is Shared
We all have the same amount of time, but we use it in different ways.
🕰️ Measuring Time
Time is measured in minutes, hours, days, weeks, months and years.
❓ EXERCISES
$1$.Estimate how many times you can do these in $1$ minute.
a. Walk around your classroom.
b. Stand up and sit down.
c. Estimate how long you can stand on one leg without wobbling.
Try it. How close was your estimate?
e. What happens at home or at school that takes about an hour to do?
f. What would you do that lasts about a day?
g. What could you do that lasts a week?
👀 Show answer
Answers will vary.
This question is about estimating and then checking with a real try. Reasonable estimates depend on classroom size, speed, and balance. For parts e–g, any sensible example that fits the time length is acceptable.
$2$.Use the calendar to find the answers.
a. How many days are between $22$nd January and $18$th February?
b. What is the date three weeks after $1$st March?
c. Carnival day is $17$th March. Plans were made six weeks before that. What date did they start planning?
d. Zalika planned a holiday to last three weeks. She left on $19$th January. When did she arrive back?
👀 Show answer
a. From $22$nd January to $18$th February is $27$ days.
b. Three weeks after $1$st March is $22$nd March.
c. Six weeks before $17$th March is $3$rd February.
d. Three weeks after $19$th January is $9$th February.
$3$.
a. Many airlines ask you to buy a ticket $14$ days before your flight. If Thandiwe is leaving on $20$th June, on what day should he buy his ticket?
b. Misha will arrive at the hotel on $8$th July and will stay three nights. What date will Misha check out of the hotel?
c. Abida was seven years old on $11$th September. Jim was seven years old on $18$th September. How many days older is Abida?
d. Stefania will be $13$ years old on $7$th October $2023$.
In what year was she born?
How old will she be on $7$th October $2030$?
👀 Show answer
a.$14$ days before $20$th June is $6$th June.
b. Arriving on $8$th July and staying three nights means checking out on $11$th July.
c.$18 - 11 = 7$, so Abida is $7$ days older.
d. Born in $2023 - 13 = 2010$. On $7$th October $2030$ she will be $2030 - 2010 = 20$ years old.
$4$.
a. How many months, weeks and days are there between $3$rd June $2022$ and $25$th November $2022$?
b. Daniele was born on $10$th January $2003$. How old will he be on his birthday in $2018$?
c. Lily’s holiday is from $9$th May to $21$st May. Song’s holiday starts on $12$th May and lasts two weeks. Whose holiday is longer and by how many days?
👀 Show answer
a. From $3$rd June to $3$rd November is $5$ months. From $3$rd November to $24$th November is $21$ days ($3$ weeks), then to $25$th November is $1$ more day. So: $5$ months, $3$ weeks and $1$ day.
b.$2018 - 2003 = 15$, so he will be $15$ years old.
c. Lily: $21 - 9 = 12$ days. Song: two weeks = $14$ days. Song’s holiday is longer by $14 - 12 = 2$ days.
$5$.Solve the calendar questions.
a. I packed a suitcase on $7$th April to visit my grandma in three days’ time. I will stay for nine days.
What day and date will I get home?
b. My friend was coming to stay on $16$th April for three days. She was ill and couldn’t come for another week. Then she stayed for $5$ days.
What day and date did she go home?
👀 Show answer
a. Three days after $7$th April is $10$th April. Staying nine days means getting home on $19$th April, which is a Tuesday.
b. One week after $16$th April is $23$rd April. Staying $5$ days means going home on $28$th April, which is a Thursday.
$6$.Only children aged $10$ and above can ride the rollercoaster. Nabil is eight years old and Gina is nine years old. How many years do they have to wait until they can both ride the rollercoaster together?
👀 Show answer
Nabil is $8$, so he needs $10 - 8 = 2$ years. Gina is $9$, so she needs $1$ year. They must wait until both are at least $10$, so they have to wait $2$ years.
🧠 Think like a Mathematician
Equipment: A minute timer
Method:
- Walk around a space or playground for $1$ minute.
- Count how many steps you take.
- Record your result.
- Think about what would happen if you walked for longer.
Follow-up Questions:
👀 show answer
- 1. Your answer depends on how fast you walk (for example, about $100$ steps).
- 2. Usually yes. If your speed stays the same, steps are proportional to time, so $2$ minutes gives about $2\times$ as many steps. It may not be exact if you slow down or speed up.
- 3. If you walk $s$ steps in $1$ minute, then in $10$ minutes you walk about $10s$.
- 4. In $30$ minutes you walk about $30s$.
- 5. In $1$ hour ($60$ minutes) you walk about $60s$.