Decide which of the given units would be the most appropriate to use
for
a) the height of a building: kilometres, metres or centimetres?
b) the mass of a pen: grams, tonnes or kilograms?
c) the capacity of a paddling pool: millilitres or litres?

For the height of a building, metres would be the most appropriate unit. While kilometres might seem like a contender for particularly tall skyscrapers, it’s much easier to convey height in metres, allowing for a clear understanding of how many floors or stories the building has. Centimetres would be too small of a unit, making measurements cumbersome.

When it comes to the mass of a pen, grams are the ideal choice. A typical pen weighs just a few grams, so using kilograms or tonnes would lead to unnecessarily large numbers that lack clarity. Grams make it simpler to express and compare the weight without any confusion!