Place Value Palace
Build the number from hundreds, tens and ones — then say which is bigger.
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
Reading, building and comparing numbers to 1000 in hundreds, tens and ones.
Three-digit place value, with comparison pairs chosen to expose the classic error rather than to be easy. When the tens and the ones point in opposite directions — 71 against 25 — children who compare digit by digit get it wrong, and a random pair rarely catches that.
- The underlying idea
- Place value determines magnitude; digit-by-digit comparison is the classic failure.
- Where this sits in Illustrative Mathematics
- 2nd grade Unit 5: Numbers to 1,000 · 2nd grade Unit 7: Adding and Subtracting within 1,000
- Sources
- Illustrative Mathematics / Kendall Hunt (2024) · Holloway et al. (2009) all references →
Related measured skills: ALPACA · Early operations, MagPI · Number comparison. What this means