Your First Steps in Algebra
Four parts in the order that makes algebra make sense rather than the order it is usually taught. Find out what a letter actually stands for, learn to tell an equation from an expression, understand why both sides must change together — and only then solve for x, by which point the method is obvious instead of arbitrary.
CodePLU Goal
Upgrading Human Mental Models
Learn how to think in Workflows
What Is a Variable, and Why Use Letters?
A letter in maths is not a mystery or a code — it is a number you have not pinned down yet. Learn the three jobs letters do, and build a letter down into each in an interactive playground.
What's the Difference Between an Expression and an Equation?
One can be simplified, one can be solved, and one gives you a range rather than an answer. Learn to tell them apart by building one stem into all three in an interactive playground.
Why Must You Do the Same Thing to Both Sides?
An equation is a claim that two sides are equal, so any change to one side alone makes it false. Learn which moves keep the balance and which ones actually help.
How Do You Solve for x, Step by Step?
Solving is undoing, in reverse order. Learn why the last thing done to x is the first thing you remove, and build the whole solution yourself.