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ChanceForge — a probability lab: young scientists rolling dot-pip dice, spinning a wedge spinner and watching a Galton board build plain colored bars, jars of marbles

ChanceForge

Roll the dice on real probability. Run experiments, watch the patterns appear, and learn why more data means clearer answers — then practice with the crew who each teach one piece of statistics.

Probability Lab Galton’s Board
Level 1

Start here

Probability Lab Flip coins and roll dice, and watch the law of large numbers settle the odds toward what theory predicts. Is It “Due”? Four heads in a row — is tails “due”? Get caught by the gambler’s fallacy, then see each flip is independent. Detective’s Dilemma A good detector still gives false alarms when the thing is rare — base-rate reasoning made visible. Chance Duel A head-to-head kit round for 2–4 players — one device or an online room by code. Highest first-try score wins.
Brain Break Take a quiet moment between rounds — a fun teaser or a short breather. Brain breaks help you remember what you learn.

All activities

Run experiments

Galton’s Board Drop beads through ten rows of pins and watch eleven bins pile up into a bell, then check it against the math. The Problem of Points A game stopped at 2–1: split the prize fairly, then count every way it could have finished, as Pascal and Fermat did in 1654. Sample-Space Grid Shade every outcome of two dice for an event, count them, and watch experiments close in on theory. Probability-Tree Builder Build a two-stage tree branch by branch and learn why you multiply along a path — not add. Fair Sample? See how a convenience sample skews the result — why HOW you sample decides if the answer is trustworthy. Read the Box Plot Read the median, the middle half, and the range straight off a box plot.

Practice & play

Mixed Practice Shuffles questions from the kits you’ve played, brought back when they’re ready to review.

Practice the concepts

16 kits from collecting data up to statistical inference — a short round with a hint whenever you get stuck.

All 16 kits
Kit 1: Data Collection & Organization Data & Displays · Grades 4–5 · 25 questions Kit 2: Graphs & Data Displays Data & Displays · Grades 4–5 · 25 questions Kit 3: Mean, Median, Mode & Range Statistics · Grades 5–6 · 25 questions Kit 4: Probability Basics Probability · Grades 5–6 · 25 questions Kit 5: Experimental vs. Theoretical Probability Probability · Grades 5–6 · 25 questions Kit 6: Compound Events & Sample Spaces Probability · Grades 6–7 · 25 questions Kit 7: Statistical Variability & Distributions Statistics · Grades 6–7 · 25 questions Kit 8: Statistical Inference & Prediction Inference · Grades 7–8 · 25 questions Kit 9: Experimental Probability Probability · Grades 5–6 · 25 questions Kit 10: Compound Events & Trees Probability · Grades 6–7 · 25 questions Kit 11: Statistical Distributions Statistics · Grades 6–7 · 25 questions Kit 12: Data-Driven Decision Making Inference · Grades 7–8 · 25 questions Kit 13: Cross-Topic Connections Data & Displays · Grades 5–6 · 25 questions Kit 14: Real-World Applications Data & Displays · Grades 6–7 · 25 questions Kit 15: Misconceptions & Reasoning Data & Displays · Grades 6–7 · 25 questions Kit 16: Advanced Synthesis Data & Displays · Grades 7–8 · 25 questions

For grown-ups — progress report →A private, on-device snapshot mapped to the skill areas practiced. Export a CSV or print — nothing that names you leaves this device.

Cast, stories & more
Where this tool comes from

Galton’s board

Francis Galton, an English scientist, built this board in the 1870s to show how chance adds up. He described it in his book Natural Inheritance (1889) and called it a quincunx; “bean machine” is a later nickname.

One thing to hold: A board with rows of pins. Lead shot pours in at the top, bounces through the pins and lands in a row of slots.

Why it matters: Each ball goes left or right by chance, yet together the balls pile into the same hump-shaped curve every time. One run is lumpy; the shape shows up when many balls fall.

Sources: Francis Galton, Natural Inheritance (1889) · Stephen M. Stigler, The History of Statistics (1986)

More ways to play

Quiz Arena Chance Run Trust the OddsBot? Loot Tables Bingo Lab Points per Shot From points to games

Same idea, another world

Something you practice here shows up somewhere else too — that's real learning that travels.

The chance of an event is favorable outcomes over the total — that is a fraction, a part compared to the whole. The shared idea: part compared to a whole — a probability is favorable outcomes over all outcomes, the same part-of-a-whole idea as a fraction Try FractionForge → Counting favorable outcomes over the total is exactly how a Punnett square predicts which traits an offspring inherits. The shared idea: probability as favorable-over-total — the favorable-over-total you compute for dice is exactly how a Punnett square predicts offspring ratios Try TraitForge → Counting all the outcomes to find a chance is the same fundamental counting principle — multiply the choices at each step. The shared idea: counting the outcomes — counting all the equally-likely outcomes for a probability is the same fundamental counting principle you multiply choices with Try DiscreteQuest →
ChanceForge mascot

Meet the cast — the characters who teach this

Each one stands for an idea you’ll practice. Tap a character to read their illustrated story and hear their audio drama.

Ensemble stories — the cast together

Explore all the stories →

What next? Pick a door

Chosen from what this app is about. What you open is remembered on this device only.

📚 Books for ChanceForge

Read the story, print a workbook, or color the cast — free PDFs to read offline or print at home.

Browse all books →

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