Measuring and Money
Primary 3 · Mathematics
Measuring and Money
Lesson 2 of 3
14 min
Let's begin
Mugisha is waiting for break. He keeps peeping at the round clock on the classroom wall.
One hand is crawling. The other hand is barely moving at all. When the long hand reaches 12, we go outside, says the teacher.
Mugisha decides he is tired of waiting for someone else to tell him the time. Today, so will you: you are going to read that clock yourself.
A clock face has the numbers 1 to 12 written all the way around it.
It has two hands, and they do different jobs.
The short hand is the hour hand. It moves very slowly. It creeps from one number to the next.
The long hand is the minute hand. It moves fast. It travels all the way around the clock in one hour.
An hour has 60 minutes. That is one whole trip of the long hand.
Worked example
The long hand points straight up at the 12. The short hand points at the 4. What is the time?
When the long hand is on 12, the hour has just started. No minutes have gone by yet.
So you simply read the short hand and say o'clock.
The time is 4 o'clock.
Worked example
The long hand is on 12 and the short hand is on 9. The time is 9 o'clock.
Careful! Do not read the long hand as the hour. If you said 12 o'clock, you looked at the wrong hand.
The long hand takes 60 minutes to go all the way round. Halfway round is 30 minutes — and halfway round lands on the number 6, pointing straight down.
When the long hand points at 6, we say half past.
Worked example
The long hand points at 6. The short hand sits between 7 and 8. What is the time?
The long hand on 6 tells you it is half past something.
Now, which hour? The short hand has already left 7, but it has not reached 8 yet. We always name the hour it has already passed.
The time is half past 7.
Half past 7 means 7 o'clock has gone by and 30 minutes have passed since then.
Worked example
The long hand is on 6 and the short hand is between 12 and 1. The time is half past 12.
Worked example
A lesson starts at 8 o'clock and ends at half past 8. How long is the lesson?
From 8 o'clock to half past 8 is half of an hour. Half of 60 minutes is 30 minutes.
The lesson lasts 30 minutes.
Worked example
Uwase starts her homework at 5 o'clock and finishes at 7 o'clock. How long did she work?
From 5 to 6 is one hour. From 6 to 7 is one more hour.
She worked for 2 hours.
Worked example
A football match runs from 2 o'clock to half past 3. How long is it?
Go in steps. From 2 o'clock to 3 o'clock is 1 hour. From 3 o'clock to half past 3 is 30 minutes more.
The match lasts 1 hour and 30 minutes.
A week has 7 days, always in this order:
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday.
Monday to Friday are school days. Saturday and Sunday are the weekend. In Rwanda, the last Saturday of the month is umuganda, when everyone works together to clean and build.
Worked example
How many days are there in 2 weeks?
One week is 7 days. So count: 7, 14.
Two weeks are 14 days.
A year has 12 months, always in this order:
January, February, March, April, May, June, July, August, September, October, November, December.
Most months have 30 or 31 days. February is the short one: it usually has 28 days, and 29 days in a leap year.
A whole year has 365 days (366 in a leap year).
Worked example
Which month comes just after August?
Say the list to yourself: July, August, September. So September comes next.
Rwanda does not have hot and cold seasons. It has rainy seasons and dry seasons, and they come round every year in the same order:
Farmers watch the calendar closely. They plant when they know the rains are coming.
Tip
Short hand, slow hand. It is the hour hand. It takes a whole hour to crawl from one number to the next.
Long hand, fast hand. It is the minute hand. It runs the whole way round in one hour.
Long hand on 12 → say o'clock.
Long hand on 6 → say half past.
And when it is half past, name the hour the short hand has already gone past — never the one in front of it.
Try each one, then tap Show answer to check.
What you learned today
Quick check
The long hand points at 12. The short hand points at 3. What is the time?
