Whole numbers are for counting collections of things.
Natural numbers are for counting collections of things that might not be there.
Integers are numbers for assessing payments and debts -- collections of things that you might owe.
Rationals numbers are for describing things that are divisible into equal parts.
Real numbers are for measuring continuously variable quantities that nonetheless shrink and grow in predictable scalar fashion depending on what unit you measure them by, like hypotenuses of triangles.
Complex numbers are for quantities that not only shrink and grow, but rotate.
These numbers... they're for sheep.