Isolating the unknown. The mechanics of solving for x — and why the same operations on both sides preserve the balance.
Volume 2 — Patterns and algebra
Volume 2
Patterns and Algebra
You already know how numbers behave. This volume is about what happens when one of the numbers is missing — and about the notation that lets you work with that absence as if it were a thing you could hold.
By the end you will be able to write a relationship down symbolically, solve for unknowns, recognise when a relationship is linear versus something else, and read a graph as a statement about how two quantities relate. These are the tools every quantitative field uses before it reaches for anything more sophisticated.
4 chapters
Grade 8–9
Needs Volume 1
Chapter Map
When the answer is a range. Solving inequalities, reading solution sets on a number line, and what flipping the inequality sign actually means.
When the relationship repeats. Arithmetic and geometric sequences, finding the nth term, and the difference between adding the same amount and multiplying by the same amount.
When the relationship has a shape. Plotting equations in the coordinate plane, reading slope and intercept, and seeing linear versus non-linear at a glance.