Clocks and Rulers
What time does the clock say? How many units long is it?
For grown-ups
- How long: 10 to 15 minutes is plenty. Short and frequent beats long and occasional — the early-numeracy trials with the largest effects ran eight weeks or less.
- When they get one wrong: the page shows the working. Read it together rather than moving straight on. Feedback that explains is worth several times more than feedback that only marks right or wrong, and that gap is wider in maths than in any other subject.
- Not timed: thinking time is the point of a book. Let silences run.
- Print it too: doing the same problems on paper a few days later is worth more than doing twice as many today.
What this practises
Telling the time to the hour and half hour, and measuring length in whole units.
Included as required curriculum coverage rather than as an evidence claim: the WWC early-childhood guide rates measurement and data recommendations only "minimal", so this strand is here because grade 1 needs it, not because a trial says it moves attainment. Measuring is framed as iterating a unit, which does connect to the place-value work.
- The underlying idea
- Measuring is repeating a unit and counting the repeats — the same composed-unit idea as place value, in a different dress.
- Where this sits in Illustrative Mathematics
- 1st grade Unit 6: Length Measurements Within 120 Units · 1st grade Unit 7: Geometry and Time
- Sources
- Illustrative Mathematics / Kendall Hunt (2024) all references →
Related measured skill: ALPACA · Early operations. What this means