Understand it
by trying it.
Big ideas make more sense when you can change the numbers. Explore probability and statistics, one experiment at a time.
Free to explore. No account needed.How big is the room?
More people. Many more possible pairs.
Change a value. See what changes.
Let curiosity take the lead.
Birthday paradox
How many people does it take for a shared birthday to become likely? Change the group size and see the answer.
Bayes’ theorem
A signal arrives. How much should it change your belief? Explore prior probability, true positives, and false positives.
Monty Hall problem
Three doors. One prize. Should you switch? Play a round, then compare both strategies across thousands of games.
Expected value
Compare a two-outcome choice by weighing each possible result by its probability.
Correlation playground
Move the dots, change the pattern, and watch Pearson’s correlation coefficient respond.
Binomial probability
Find the chance of exactly, at most, or at least a chosen number of successes in repeated trials.
Law of large numbers
Follow a running proportion across thousands of coin flips and see why short runs can mislead.
Central limit theorem
Take samples from a skewed population and watch their averages form a different distribution.
Change a number. Test a hunch.
Find the idea that finally clicks.