Unit conversions

Number

These are original practice questions, not a past paper. This site is independent and not affiliated with AQA or Pearson.

Convert $3.5$ km to metres, and $450$ cm to metres.

2 marks
Convert $750$ ml to litres, and $2.4$ kg to grams.

2 marks
Use $1$ inch $= 2.5$ cm. Convert $8$ inches to centimetres, and $1$ m to inches.

3 marks
A jug holds $1.5$ litres. A glass holds $250$ ml. How many full glasses can be poured from the jug?

3 marks
Convert $72$ km/h to metres per second.

4 marks
Convert $3$ m$^{2}$ to cm$^{2}$, and $25000$ cm$^{2}$ to m$^{2}$.

4 marks
A fish tank is $0.8$ m long, $50$ cm wide and $40$ cm high. Find the volume in cm$^{3}$ and the capacity in litres.

5 marks
A path is $2.4$ m long and $75$ cm wide. Find its area in m$^{2}$ and in cm$^{2}$. Gravel is spread at $8$ kg per m$^{2}$ and sold in $5$ kg bags. How many bags are needed?

6 marks

Mark scheme

Answer. $3500$ m and $4.5$ m
- $3.5 \times 1000 = 3500$ m.
- $450 \div 100 = 4.5$ m.
Answer. $0.75$ litres and $2400$ g
- $750 \div 1000 = 0.75$ litres.
- $2.4 \times 1000 = 2400$ g.
Answer. $20$ cm and $40$ inches
- $8 \times 2.5 = 20$ cm.
- $100 \div 2.5 = 40$ inches.
Answer. $6$
- $1.5$ litres $= 1500$ ml.
- $1500 \div 250 = 6$.
Answer. $20$ m/s
- $72$ km/h $= 72000$ m/h.
- $72000 \div 3600 = 20$ m/s.
Answer. $30000$ cm$^{2}$ and $2.5$ m$^{2}$
- $1$ m$^{2} = 10000$ cm$^{2}$, so $3$ m$^{2} = 30000$ cm$^{2}$.
- $25000 \div 10000 = 2.5$ m$^{2}$.
Answer. $160000$ cm$^{3}$, which is $160$ litres
- $0.8$ m $= 80$ cm.
- Volume $= 80 \times 50 \times 40 = 160000$ cm$^{3}$.
- $1000$ cm$^{3} = 1$ litre, so the capacity is $160$ litres.
Answer. Area $1.8$ m$^{2}$ ($18000$ cm$^{2}$). Mass $14.4$ kg, so $3$ bags.
- $75$ cm $= 0.75$ m, so the area is $2.4 \times 0.75 = 1.8$ m$^{2}$.
- $240 \times 75 = 18000$ cm$^{2}$.
- Gravel: $1.8 \times 8 = 14.4$ kg.
- $2$ bags are only $10$ kg, so $3$ bags are needed.