SEAGReady
MeasurementP6 level21 questions in the full course

Convert Length UnitsSEAG Practice Questions

Converting between kilometres, metres, centimetres, and millimetres using multiplication and division by 10, 100, and 1000.

Where your child meets this in real life: Converting height from centimetres to metres (e.g., 175 cm = 1.75 m)

What your child needs to know

SEAGReady breaks convert length units into 3 steps, taught in order so each skill builds on the last.

  1. 1

    Metres and Centimetres

    Convert between metres and centimetres using multiplication by 100 and division by 100

  2. 2

    Centimetres and Millimetres

    Convert between centimetres and millimetres using multiplication by 10 and division by 10

  3. 3

    Kilometres and Metres

    Convert between kilometres and metres using multiplication by 1000 and division by 1000

Try these SEAG-style questions

Three free sample questions from our convert length units course. Every question comes with a full explanation, and hints that guide without giving the answer away.

Question 1Confidence builder

Sean is measuring his living room for new furniture. The room is 3 metres long. How many centimetres is this?

  • A300 cm
  • B30 cm
  • C3 cm
  • D3000 cm
Show answer and explanation

Answer: A. 300 cm

To convert metres to centimetres, multiply by 100. 3 m x 100 = 300 cm The room is 300 cm long.

Stuck? Start here: Remember: centi means one hundredth, so there are 100 cm in 1 m.

Question 2Confidence builder

Declan found a beetle that is 20 millimetres long. How many centimetres is this?

  • A2 cm
  • B200 cm
  • C0.2 cm
  • D20 cm
Show answer and explanation

Answer: A. 2 cm

To convert millimetres to centimetres, divide by 10. 20 mm ÷ 10 = 2 cm The beetle is 2 cm long.

Stuck? Start here: Remember: there are 10 mm in 1 cm.

Question 3Confidence builder

The distance from Aoife's house to the park is 3 kilometres. How many metres is this?

  • A3000 m
  • B300 m
  • C30 m
  • D30000 m
Show answer and explanation

Answer: A. 3000 m

To convert kilometres to metres, multiply by 1000. 3 km x 1000 = 3000 m The distance is 3000 m.

Stuck? Start here: Remember: kilo means one thousand, so 1 km = 1000 m.

Try the lesson: Metres and Centimetres

This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.

Aoife is measuring her bedroom for new carpet. The room is 4 metres long.

How many centimetres is this?

4 m = ? cm

Recall the conversion factor
1

Centi means one hundredth, so 100 cm = 1 m

Step 1 of 4

Prefer to read? See every step written out

Aoife is measuring her bedroom for new carpet. The room is 4 metres long.

How many centimetres is this?

  1. 1

    Recall the conversion factor

    • Centi means one hundredth, so 100 cm = 1 m
  2. 2

    Multiply to convert to smaller units

    • Smaller units need a bigger number
    • Multiply by 1004 × 100 = 400
  3. 3

    Write the answer with units

    • The room is 400 cm long

Aoife's bedroom is 400 cm long.

The key insight: When converting to smaller units, the number gets bigger - more little pieces fit!

Watch out: 4 m = 4 cm (dividing instead of multiplying). Centimetres are smaller than metres, so you need MORE of them, not fewer.

Mistakes to watch for

These are the misconceptions we see most often in convert length units, including the ones our practice questions are specifically designed to catch.

  • Multiplying when converting to larger units (e.g., cm to m)
  • Forgetting there are 100 cm in a metre but 1000 m in a kilometre

Build these skills first

Struggling with convert length units? The real gap is often in one of these earlier topics.

More measurement practice

21 questions on this topic alone

Master convert length units and everything it unlocks

SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.