Lemma is a math game about exploring a continent of harbors, forests, cities and ruins. Every place is a new topic, from arithmetic to algebra and statistics, and each lesson you clear opens the way a little further.
Free to play in your browser or on your mobile device. No account needed to start.
How it works
Each place on the map teaches one topic, from numeral systems in a lighthouse to geometry in the ruins of Meridian. Clear its lessons and the way on to the next place opens.
Every harbor, forest and city covers one area of math. You move on by clearing its lessons, not by turning a page, and the map fills in as you go.
Each lesson is a short timed round, and your medal shows how well you know it. Come back for a better one whenever you like. Checkpoints test a whole stretch before you move on.
Arithmetic, numeral systems, algebra, geometry, statistics and probability, each topic set up by the one before it. New lessons arrive with every update.
See the full curriculum
The world
Everyone starts at Tally Harbor. From there the road heads inland, and further on it splits, so you choose where to go next.
The first stop. Order of operations, negative numbers, roots and exponents, fractions, decimals and percent.
Inland, under the pines. Ratios, variables, factoring and your first linear equations, then unit rates, percent change and interest.
Past the forest the road keeps going: farmland, a walled city, a fishing village, ruins on a headland, and islands out at sea. Each one is a subject of its own.
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