Example 1 · level 1 — a gentle start
Convert 13 km to m.
- 13000
- 13
- 130
- 0.013
Answer: 13000 — There are 1000 m in one km.
11+ unit conversion questions
Unit conversion comes up in the maths paper of every major 11+ format. Here is what the questions look like, the method that works under time pressure, and five worked examples with the full reasoning, from a gentle start to a hard paper.
Maths · examined by GL and CEM · 5 worked examples
What your child needs to know
- Decide the direction first. Going to a SMALLER unit means MORE of them, so the number grows.
- 1 cm = 10 mm · 1 m = 100 cm · 1 km = 1000 m · 1 kg = 1000 g · 1 litre = 1000 ml
Where marks get lost: Check your answer looks sensible. If 3 m came out as 0.03 cm, you went the wrong way.
Worked examples
Every question below is generated by the same engine your child practises on, and every answer is derived by our checker rather than written by hand — which is why we can put them on a public page at all.
Example 2 · level 2 — typical of early practice
Convert 66 km to m.
- 66
- 660
- 66000
- 0.066
Answer: 66000 — There are 1000 m in one km.
Example 3 · level 3 — standard paper difficulty
Convert 251 litres to ml.
- 251000
- 2510
- 0.251
- 251
Answer: 251000 — There are 1000 ml in one litres.
Example 4 · level 4 — a harder paper
Convert 61000 ml to litres.
- 610000
- 61000
- 61
- 61000000
Answer: 61 — There are 1000 ml in one litres.
Example 5 · level 5 — the level that separates candidates
Convert 39800 cm to m.
- 398000
- 3980000
- 39800
- 398
Answer: 398 — There are 100 cm in one m.
How to practise this at home
- Work in short, frequent sessions. Ten minutes daily beats an hour at the weekend, because the recall gap is what builds memory.
- Insist on written working, even for questions your child can do in their head — under exam pressure the method is what survives.
- When an answer is wrong, ask them to explain their reasoning before you correct it. The error is almost always in one step, not the whole approach.
Practise unit conversion with a tutor that explains
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