100 Essential Math Concepts

The math on the SAT subject tests covers a lot of ground—from arithmetic to
algebra to geometry.

Don’t let yourself be intimidated. We’ve highlighted the 100 most important
concepts that you’ll need for Math 1 and listed them in this chapter.

Use this list to remind yourself of the key areas you’ll need to know. Do four
concepts a day, and you’ll be ready within a month. If a concept continually
causes you trouble, circle it and come back to it as you try to do the questions.

You’ve probably been taught most of these concepts in school already, so this
list is a great way to refresh your memory.

NUMBER PROPERTIES

1 . Number  Categories

Integers    are whole   numbers;    they    include negative    whole   numbers and

zero.

A   rational    number  is  a   number  that    can be  expressed   as  a   ratio   of  two

integers.   Irrational  numbers are real    numbers—they    have    locations   on  the

number  line—but    they    can’t   be  expressed   precisely   as  a   fraction    or  decimal.

The most    important   irrational  numbers are     and π.