Here is a road sign on the way west. It reads Gaillimh 8 km. How far do you think a kilometre is? Would it take more steps than walking right across our yard, or fewer? Hands up if you think it is longer than the yard.

The converter shows a ladder with kilometres above metres and a ×1,000 tile between them. Look at each conversion on the ladder, from kilometres down to metres and back up. See if you can predict each answer before it is shown.

Today we work through four conversions together, reading each one off a signpost. All four go the same way, from kilometres down to metres: 4 km, then 7 km, then 2 km, and finally 5 km. Before each pupil sets the ladder, the whole class gives a quick signal — thumbs up if we multiply (km to m), thumbs sideways if we would divide. Then we say the answer aloud and check it on the ladder.

Today we solve these distance problems together, and we estimate first each time before we work it out exactly. To give an estimate, hold your hands apart to show roughly how far, then one pupil says an estimate aloud.

First we work one addition on the board together, because the distances are in different units. A cycle is 2 km and then a walk is 500 m. How far is that altogether in metres? We rename both into the same unit first, then add.

After that worked example, we take the challenge problems in order: a 2 km walk in metres, then a 1,200 m cycle compared to 1 km, then two runs of 3 km and 2,500 m to compare, and finally three 400 m laps altogether.