Length, Capacity and Mass
Counting copies of a unit
To measure anything, do three things: choose a unit, lay down copies of it with care, and count them. That single recipe covers all three attributes this unit meets — how long a thing is, how much it holds, how heavy it feels. Length counts sticks along an edge, capacity counts cups poured in, mass counts blocks that balance it. The answers look different but the act is identical, and so is the warning: a count without its unit — just 6 — tells you nothing at all.
No gaps, no overlaps, no excuses
Length comes first because the counting is visible. Sticks go end to end along the surfboard: no gaps, because empty space is not board; no overlaps, because no part of the board deserves counting twice. When the last stick lands flush with the tail, the count is the measurement — the board simply is 9 sticks long. Paddle-pop sticks make a fine classroom unit precisely because they are all the same, which is the idea the next visualisation puts under pressure.
Uniform or useless
Uniform is the upgrade word of Year 2. A thong, a pencil and a stick can be laid along a bench and counted, but the resulting 5 is a number nobody can trust, repeat or compare — measure again tomorrow with different objects and the bench changes length. Six identical sticks tell a different story: anyone, on any day, with the same sticks, gets 6. Measurement is a promise of repeatability, and only uniform units can keep it.
Capacity is counted in cups
Capacity asks how much a container holds, and the cup is its paddle-pop stick: one chosen unit, poured again and again until full. Counting cups turns holds more from an argument into arithmetic — 12 beats 8 by exactly 4. Watch the trap the two containers set: the narrow bucket rises faster with every cup and looks like the keen one, but the wide esky quietly swallows more. Height is not capacity; the count is.
Mass sits on a seesaw
Mass is measured on a seesaw. Whatever is heavier drags its side down, and when the beam sits level the two sides hold equal mass — so a footy that balances 7 glue sticks has, in stick units, a mass of 7. Children have hefted objects in two hands since Year 1; the balance does the same comparing, but against a counted pile of identical units, which is what turns heavier than into a number.
When the unit is too big
Sometimes the unit refuses to fit evenly: six sticks and an awkward leftover. And a bit is honest but useless — you cannot compare, record or repeat a bit. The cure is written into the descriptor: reach for a smaller unit when accuracy demands it. Sixteen paperclips cover the skateboard exactly. The trade is plain — smaller units mean bigger counts and more careful laying — but the answer earns the right to be called exact. Formal units will inherit this idea next year.
Fair contests share a unit
A comparison is a contest, and contests need fair rules. Eight paperclips against five sticks sounds like a win for eight, yet the shorter towel collected the bigger count, because little units are cheap to collect. Before comparing, agree on the unit; remeasured in sticks alone, the contest tells the truth. This one discipline — same unit or no comparison — is the entire reason the wider world settled on shared units for everyone, a story that begins properly in Year 3.