JCHL Algebra 18: Inequalities 1

You’ll learn

• N = the natural numbers: the whole positive numbers 1, 2, 3, 4, … Zero is NOT a natural number, because it is not positive
• Z = the integers: all the whole numbers, including the negative ones and zero — …, −2, −1, 0, 1, 2, …
• R = the real numbers: every number on the number line, including decimals and fractions as well as the whole numbers
• The ∈ symbol just means "is an element of" — x ∈ N is telling you which numbers you are allowed to use in your answer