Measurement and converting
Length, mass and capacity: choose the right unit, read a scale and convert. Read one step, play with it, then tap “I understand this”.
Length, mass and capacity
| We measure | Units | Remember |
|---|---|---|
| Length: how long | mm, cm, m, km | 10 mm = 1 cm 100 cm = 1 m 1 000 m = 1 km |
| Mass: how heavy | g, kg | 1 000 g = 1 kg |
| Capacity: how much it holds | mℓ, ℓ | 1 000 mℓ = 1 ℓ |
Which unit?
Choose the unit that fits best.
Correct: 0Measure with a ruler
Put the start of the object at the 0 of the ruler, not at the edge. Then read where it ends.
Measure the pencil
Change the pencil’s length and read the ruler.
Mass: read a scale
First check what each mark on the scale means before you read it. Not every mark is 1!
The kitchen scale
Change the mass and watch the needle.
Capacity: read a measuring jug
Hold the jug straight and read at the top of the water, with your eyes at the same height.
The measuring jug
Pour water in or out and read the jug.
Convert
From a big unit to a small unit: multiply. From small to big: divide.
The converting machine
Choose the units and the direction, and change the number.
Think of money: R1 = 100c. One big unit (R1) is lots of small units (100c). The same with 1 m = 100 cm.
In measurement we use a comma for decimals: 1,5 kg = 1 kg 500 g = 1 500 g.
A smaller unit fits in more times. 1 m has 100 cm, so 3 m is 3 × 100 = 300 cm. More small pieces means a bigger number, but the length stays the same.
Check yourself
- Length: 10 mm = 1 cm, 100 cm = 1 m, 1 000 m = 1 km.
- Mass: 1 000 g = 1 kg. Capacity: 1 000 mℓ = 1 ℓ.
- Big to small unit: multiply. Small to big: divide.
- Read the scale first: not every mark is 1.
Write these points in your maths book. Read them again the night before the test.
Quick questions
Tap an answer. If you get one wrong, read why and go back to that step. You get new questions every time.
You ticked all 5 steps! Now you are ready for the quiz.- Practice sheet for this classQuestions + memo · 2 A4 pagesPractice sheet
- Measurement8 pages · PDFPaperMemo
Ready for more? The Grade 4 measurement quiz gives you new questions every time.
- One step a day is enough. Ten calm minutes work better than an hour the night before the test.
- Cook or bake together: let your child weigh the flour and measure the milk in a jug. Measurement becomes something they did themselves.
- Ask your child to tell you the rule in their own words. If they can explain it, they understand it.
- The ticks (“I understand this”) are saved on this device only. We never ask for names or emails.
Follows CAPS for Grade 4 Maths. Always check your teacher’s notes and textbook too.