Unit converter

Use it whenever units get in the way of the idea: converting a walking distance from kilometres to metres and centimetres, comparing speeds, pressures or energies, or turning grams into moles in chemistry. Seeing the same quantity written in different units helps students separate the quantity itself from the number used to express it.

The converter covers length, area, volume, mass, speed, temperature, pressure, energy, power, force, density, frequency, angle and chemistry.

1. In a worksheet, use the + between two items and choose Unit converter.

2. Click the pencil to open it. Choose the Category, then the units under From and To, and type the Value. Decimal places sets how precise the result is.

3. Choose the Display mode. Saved conversion shows students only the result you set up. Interactive converter lets them change the value and the units themselves.

4. Give it a title, for example "How long is the route?", and click the tick.

In the Chemistry category, converting between mass and amount of substance needs a Chemical formula; the converter then shows the molar mass as well.

With a Saved conversion, students see one line such as "1 km to 1000 m" and can copy the result.

With an Interactive converter, they type their own value, choose other units and can swap them with one click, and the result updates straight away. What they change is only on their screen: your saved setup stays as it was, and nothing is recorded.

• A new converter starts as a Saved conversion. Switch it to Interactive converter if students should try values themselves.

• Start from a value students know, such as the distance to school, then change the value or the unit and ask what changes in the number and what does not.

• Choose fewer decimal places for younger students, so the result reads cleanly.