Time and Data
How long did it take? And what does the graph say when each square is worth five?
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
Elapsed time to the minute, and reading a scaled bar graph.
Required grade-3 coverage. Both halves are deliberately framed as number line work, which is the part with real support: elapsed time is a jump along a line in units of sixty, and a scaled bar graph is a line with a multiplier. That also makes the scale the thing being taught, which is where children actually go wrong.
- The underlying idea
- Elapsed time is a distance on a number line whose units are sixties. A scaled graph is a number line with a multiplier.
- Where this sits in Illustrative Mathematics
- 3rd grade Unit 6: Measuring Length, Time, Liquid Volume, and Weight · 3rd grade Unit 1: Introducing Multiplication
- Sources
- Illustrative Mathematics / Kendall Hunt (2024) · Schneider et al. (2018) all references →
Related measured skills: ALPACA · Elementary operations, MagPI · Number line estimation. What this means