Here are three jobs someone might have to do at home: put a fence around a garden bed, lay a carpet on a floor, and pack a box full of blocks.

They all use maths, but a different kind for each one. Which job is about the distance around the edge? Which is about the flat space inside? And which is about the solid space that gets filled right up?

Three shapes appear one at a time. Watch how we measure each one, and keep an eye on the units. Same idea, different amounts of space. Then we count the cubes in a box for volume, one layer then the stack.

Today we work through these together on the board, deciding the measure each time before we work it out: first a 7 cm by 3 cm rectangle where we find the perimeter, then the same 7 cm by 3 cm rectangle where we find the area, then a 4 cm by 4 cm square where we find both. Naming the measure first is the tricky part, so we say it aloud before we type anything. One of us types the answer and presses Check, and Next brings the next question.