Running 24-Point Activities in Your Classroom: A Teacher's How-To

Setup: none, honestly

You need nothing but this site and a projector. Open the daily puzzle, or print a batch of worksheets before class. There are no accounts to create, no apps to install, and nothing to configure. If a projector isn't available, reading four numbers aloud works fine — students write them down and go.

A 20-minute lesson outline

1. Warm-up (3 min). Project one hand. Silent thinking time first — no calling out. This protects slower processors and makes the eventual discussion richer.

2. Pairs (10 min). Students work in pairs. Most hands at the easy or medium tier are solvable in under two minutes, so a worksheet row of 4–6 hands is a good session. Early finishers get expert hands — there are only 16 in existence, and they are genuinely hard.

3. Share-out (5 min). Pick one contested hand and open it in the solver on the projector. Ask a pair that solved it to explain their route before revealing all solutions — students are consistently surprised that one hand can have many legitimate paths (the record is 22 distinct solutions on a single hand).

4. Exit ticket (2 min). Each pair writes one hand they solved and the seed of their worksheet. That seed is your assessment hook — more below.

Differentiation

• Tier by hand difficulty, not by student label. The easy tier has 216 hands, medium 181, hard 949, expert 16. It's normal for a strong student to stall on a hard hand and a quiet one to spot the key move on a medium. Let pairs choose their starting tier; you adjust from there.
• Whole-number rule as a scaffold. Play "integer intermediates only" for beginners — it's the classic classroom variant, and 1,346 of the 1,362 solvable hands can be solved that way.
• The fraction extension. The 16 hands that require fractions (including 3 3 8 8) are a ready-made extension task for students who need more. See the pitfalls section before unleashing them.

Assessment ideas

• Seeds are your friend. Every worksheet is generated from a deterministic seed; the same seed always prints the identical sheet. Collect the seed, not the paper: you can reprint the exact sheet for a retest, for absent students, or to compare classes on identical content.
• Record strategy, not just answers. During circulation, note how pairs solve: factor-pair reasoning (3×8, 4×6, 12×2) is the benchmark strategy; random-operation guessing suggests they need the how-to-play guide.
• Data lesson (older students). Download the open dataset — all 1,820 combinations as JSON/CSV — and have students test claims: "Are expert hands rarer than 1%?" "What fraction of hands are unsolvable?" (It's 458 out of 1,820, about a quarter.)

Common pitfalls and how to handle them

"This hand is impossible." Students swear 3 3 8 8 has no solution — and every whole-number path really does fail. Write 8 ÷ (3 − 8 ÷ 3) = 24 on the board and let the fraction land: 3 − 8/3 = 1/3, and 8 ÷ (1/3) = 24. The full breakdown is on the 3 3 8 8 solution page. This single reveal converts skeptics better than any explanation.

The reverse trap also exists. Students sometimes declare a hand unsolvable when it isn't. The solver settles it instantly — and it's worth teaching students to check before giving up, since 1,362 of the 1,820 hands do have solutions.

Fraction anxiety. Before any fraction hand, establish the comfort rule: intermediates stay whole unless you choose the expert variant. Fun counterexample for confident classes: 4 4 10 10 looks like it needs fractions, but (10 × 10 − 4) ÷ 4 = 24 uses whole numbers all the way.

Speed pressure. The game rewards persistence more than velocity. Frame unsolved hands as "still working," not "failed" — the fastest useful habit is testing the factor pairs systematically.

More resources

• Generate printable worksheets — with answer keys and shareable seed links.
• Browse all hands and tiers — every hand's full solution set.
• Teachers overview page — tools and classroom patterns in one place.