Number Systems
Map
Arrows point from what you learn first to what it opens.
- Proven to level123
- Open
- Locked
- Comes back deeper
Learning path
In the order the concepts build on each other.
- Natural numbersReadyThe counting numbers 1, 2, 3, ... - what you get by starting at one and repeatedly adding one more.
- IntegersLockedThe natural numbers together with zero and their negatives - the numbers you need so that subtraction always has an answer.Opens after: Natural numbers
- Rational numbersLockedNumbers that can be written as a fraction p/q of two integers with q not zero - the numbers you need so that division always has an answer.Opens after: Integers
- Irrational numbersLockedNumbers on the number line that cannot be written as a fraction of integers, like √2 and π. Their decimals never end and never repeat.Opens after: Rational numbers
- Real numbersLockedAll the rational and irrational numbers together - every point on the continuous number line, with no gaps.Opens after: Rational numbers, Irrational numbers
- Complex numbersLockedNumbers of the form a + bi, where i is a number with i² = -1. They give every polynomial equation a solution.Opens after: Real numbers