Concept · 4 steps · NESA MA4-ALG-C-01

Creating Algebraic Expressions & Evaluating by Substitution

Letters that stand in for numbers — the whole of algebra in one idea. Once you can swap a value in for a letter and work it out, formulas stop being scary.

1Where it comes fromA letter is just a placeholder for a number. Slide it and watch. 2How to do itSubstitute, then evaluate — with a practice generator. 3Where it gets tricky2x vs x², and the negatives that catch everyone. 4Out in the wildReal formulas — cost, perimeter — and working backwards.

← This concept rests on

Order of Operations
Multiplying Whole Numbers

→ It unlocks

Simplifying Expressions
Solving Linear Equations
Plotting Straight-line Graphs