Sat math Essentials

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T E C H N I Q U E S A N D S T R AT E G I E S
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R e a l N u m b e r s
All numbers on the SAT are real numbers. Real numbers include the following sets:
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Whole numbers
are also known as counting numbers.
0, 1, 2, 3, 4, 5, 6, . . .
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Integers
are positive and negative whole numbers and the number zero.
. . . –3, –2, –1, 0, 1, 2, 3 . . .
■
Rational numbers
are all numbers that can be written as fractions, terminating decimals, and repeating
decimals. Rational numbers include integers.
3
4
2
1
0.25
0.38658
0.6
6
6
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Irrational numbers
are numbers that cannot be expressed as terminating or repeating decimals.
π
2
1.6066951524 . . .
C H A P T E R
Numbers and
Operations
Review
This chapter reviews key concepts of numbers and operations that you
need to know for the SAT. Throughout the chapter are sample ques-
tions in the style of SAT questions. Each sample SAT question is fol-
lowed by an explanation of the correct answer.
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Practice Question
The number –16 belongs in which of the following sets of numbers?
a.
rational numbers only
b.
whole numbers and integers
c.
whole numbers, integers, and rational numbers
d.
integers and rational numbers
e.
integers only
Answer
d.
–16 is an integer because it is a negative whole number. It is also a rational number because it can be
written as a fraction. All integers are also rational numbers. It is not a whole number because negative
numbers are not whole numbers.