Year 4 · Measures, time and graphs
Converting units of measure
Convert between different units of measure, for example kilometre to metre and hour to minute
Lesson overview
What you'll learn in this lesson
Convert between different units of measure, for example kilometre to metre and hour to minute
Key learning points
- • Learn the six facts
- • Bigger unit to smaller: multiply
- • Smaller unit to bigger: divide
- • Comparing mixed units
This lesson at a glance
- 20 minutes
- 18 parts to scroll through
- 4 quick checks
- No marked quiz yet
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 18
Watch first
Converting units of measure
Measuring round the edge, covering the inside, then reading the clock.
Read the film in words (English) ↓
What the film shows
- A finger traces the edge of a rectangle while the perimeter total counts up.
- The same rectangle fills with unit squares to show its area.
- Units convert on screen: centimetres to metres, grams to kilograms, millilitres to litres.
- A 12-hour clock and a 24-hour clock show the same moment side by side, then a bar chart is read off.
- The perimeter and unit-swap practicals for this unit repeat all of this with a tape measure.
Do it for real
The practicals below use what the film shows, with a full method you can follow at home.
In a nutshell
Convert between different units of measure, for example kilometre to metre and hour to minute
What you already know
Part 2 of 18
Before we start
What you already know
You can multiply and divide by 10, 100 and 1000.
Key words
Part 3 of 18
Key words
Words you'll need today
- kilometre
- 1,000 metres.
- centimetre
- One hundredth of a metre — 100 cm in a metre.
- millilitre
- One thousandth of a litre — 1,000 ml in a litre.
Learning cycle
Part 4 of 18
Learning cycle 1 of 2
Part 1 — The facts you need
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 5 of 18
Learn
Learn the six facts
1 km = 1,000 m. 1 m = 100 cm. 1 cm = 10 mm. 1 kg = 1,000 g. 1 litre = 1,000 ml. 1 hour = 60 minutes. Nearly every conversion question in Year 4 uses one of these six.
Explore the idea
Part 6 of 18
Learn
Bigger unit to smaller: multiply
Going from km to m, you get more of them, so multiply: 3 km = 3,000 m. 2.5 kg = 2,500 g. 4 m = 400 cm. If your answer got smaller, you have gone the wrong way.
Quick check
Part 7 of 18
Quick check
5 km = ? m
Reset break
Part 8 of 18
Pause
That's sitting 1 of 2 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Quick check
Part 9 of 18
Quick check
2,400 g = ? kg
Learning cycle
Part 10 of 18
Learning cycle 2 of 2
Part 2 — Converting either way
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 11 of 18
Learn
Smaller unit to bigger: divide
1,500 g = 1.5 kg. 250 cm = 2.5 m. 90 minutes = 1 hour 30 minutes. Time is the odd one out, because it divides by 60 rather than 10, 100 or 1000.
Explore the idea
Part 12 of 18
Learn
Comparing mixed units
Which is longer, 180 cm or 2 m? Change both to the same unit: 2 m = 200 cm, so 2 m is longer. Never compare numbers until the units match — that is the whole skill.
Quick check
Part 13 of 18
Quick check
3 m = ? cm
Quick check
Part 14 of 18
Quick check
2 hours 15 minutes = ? minutes
Common mix-ups
Part 15 of 18
Common mix-ups
Things people often get wrong
- Dividing when you should multiply, so 3 km becomes 0.003 m.
- Using 100 for time, giving 1 hour 40 minutes as 140 minutes.
- Comparing 180 cm with 2 m without converting.
Challenge round
Part 16 of 18
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Mastery quiz
Part 17 of 18
No quiz for this one
This lesson has no marked quiz attached yet.
Lesson round-up
Part 18 of 18
Lesson round-up
Ready when you are
Quiz score
Not sat
Games
Not played
Points this lesson
0
Best run
0 in a row
Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?
Ask LunaDo the work
Your written work for this lesson
This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.
The cost of a school trip
A school is planning a trip to a wildlife park. The coach costs £480 however many people go. Entry costs £9.50 for each pupil and each adult goes free. The school says every pupil must pay the same amount, and the trip must not lose money.
If 60 pupils go, the coach works out at £8 each, so the total for each pupil is £17.50. If only 40 pupils go, the coach works out at £12 each, so the price rises to £21.50. The teacher explains that the coach is a fixed cost and the entry is a cost per person — which is why the price per pupil changes when the number changes.
The school decides to charge £20 and to use anything left over for a second trip later in the year.
Written for Good Learning Co.
Reading questions
- Work out the total cost of the trip if 50 pupils go.
- Show why the price per pupil falls when more pupils go, using numbers.
- At £20 each, how many pupils must go before the trip makes money? Show your working.
Working out
Working outDo the practice questions on paper, showing every step — not just the answer. Mark them yourself and circle anything you got wrong.
10–15 questions
Worked example, explained
WritingCopy one question out and write underneath, in words, why each step works.
1 question, 4–5 sentences
Problem in words
Working outWrite your own real-life problem that uses today's method, then solve it.
1 problem + solution
Saved as you type.
Part 1 of 18 · Watch & discover