Quick question on the board: what is 4.7 metres in centimetres?

Think it through quietly for a few seconds, then hands up. If you already know the rule, you'll share it with the class; if it's gone fuzzy since the last time you used it, listen and see if it comes back as we go.

Watch four length conversions. Each time, look for the same pattern: changing to a smaller unit (like centimetres) gives a bigger number, and changing to a bigger unit (like metres) gives a smaller number.

Example 1: Metres to Centimetres

Example 2: Kilometres to Metres

Example 3: Millimetres to Centimetres

Example 4: Kilometres to Metres

Now we drive the interactive together. Pupils take turns at the board to tap a rung and convert a real length.

Lengths we will try: a 3.2 m corridor banner in centimetres, a 0.4 km Westport laneway in metres, and a 75 cm school chair in millimetres.