**Question**: What do the letters R, Q, N, and Z mean in math?

**Answer**: The letters R, Q, N, and Z refers to a set of numbers such that:

R = real numbers includes all real number [-inf, inf]

Q= rational numbers ( numbers written as ratio)

N = Natural numbers (all positive integers starting from 1. (1,2,3….inf)

z = integers ( all integers positive and negative ( -inf, …, -2,-1,0,1,2….inf)