# Mathematical Notations

**A List of Notations based on Introductory College Algebra by Rietz and Crathorne (1929)**

+, read *plus*. -, read *minus*.

X, or *, or ∙, read *times* or *multiply*.

÷, or /, read *divided by*.

=, read *is equal to*.

≈, read *is approximate to*.

≡, read *is identical to*.

≠, read *is not equal to*.

→, read *approaches*.

<, read *is less than*.

>, read *is greater than*.

≤, read *is less than or equal to*.

≥, read *is greater than or equal to*.

∩, read *intersection*.

U, read *union*.

a!, read *factorial a*.

( ) Parentheses.

[ ] Brackets.

{ } Braces.

a_{r}, read *a subscript r*, or *a sub r*.

x’, x”, ∙∙∙, read *x prime*, *x second* or *x double prime*, ∙∙∙ respectively.

lim x, read *limit of x*.

x → ∞, read *as x goes to infinity*.

|a|, read *absolute value of a*.

an, read *a to the nth power*, or *a exponent n*.

√a, read *square root of a*.

f(x), φ(x), etc. read *“f” function of x, “φ” function of x,* etc.

(x,y), read *point whose coordinates are x and y*.