Numbers
How many? How much? Arithmetic helps us count and calculate; number theory explores the deeper properties of integers.
Mathematics helps us find patterns, explain relationships, and turn a good question into something we can understand.
Explore the ideasThe study of patterns, structure, space, and change — built from precise definitions, logical reasoning, and proof.
These are starting points, not separate worlds. The most interesting ideas often connect them.
How many? How much? Arithmetic helps us count and calculate; number theory explores the deeper properties of integers.
Use symbols to describe relationships and reason about unknown values. One expression can represent many different situations.
Geometry studies shapes and space. Calculus studies rates of change and accumulation, linking motion, slopes, and areas.
Probability models chance. Statistics uses data to estimate, compare, and draw conclusions while accounting for uncertainty.
Arrange dots in a square. A square with n dots on each side contains n² dots. Increase the side length by one and notice the new outer row and column.
5² = 25
Growing from 4 × 4 adds 9 dots: 2 × 5 − 1.
Green: the previous square. Gold: the new dots.
A calculation can tell you what happens in one case. A mathematical argument can explain why it must happen in every case covered by its assumptions.
The first square numbers are 1, 4, 9, 16, 25. Their differences are 3, 5, 7, 9: consecutive odd numbers.
For any positive integer n, the difference between n² and (n − 1)² is 2n − 1.
Expand the brackets: n² − (n² − 2n + 1) = 2n − 1. The dot diagram shows the same idea as a growing border.
You do not need to know every formula.
You need a question worth exploring.
Count something. Sketch a shape. Look for a pattern.
Then ask what makes it true.