Name ________________________________________ Date __________________
LESSON
1-1
Class _________________
Reteach
Sets of Numbers
As you move from left to right on a number line, the numbers increase.
Use a number line to help you order real numbers.
Order from least to greatest:
1 
11,  2.6, ,  , 2.354.
2 2
Use a calculator to approximate
11  3.32 and 
11 and 

as decimals:
2

 1.57.
2
Plot each point on a number line.
Read the numbers from left to right on the number line.
 1
From least to greatest, the order is 2.6,  , , 2.354, 11.
2 2
Order the given numbers from least to greatest. Use a number line to
help you.
2
, 0.456, and 3
3
2
  3.14, 2  2.67, and 3  1.73
3
1. , 1.9 , 2
2. 1.75, 1,
1
, 1.55, and  5
5
1
 ____________
5
 5  ____________
____________________________
1
3. 6,  2.63,  4.36, 2 3, and 
6
6  ____________
2 3  ____________
1
  ____________
6
____________________________
Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor.
1-6
Holt Algebra 2
Name ________________________________________ Date __________________
LESSON
1-1
Class _________________
Reteach
Sets of Numbers (continued)
You can represent the same set in different ways.
Number line:
Words: The set of numbers greater than or equal to 2 and less than 0
OR greater than or equal to 1
 means infinity and
– means negative infinity.
Interval Notation: [2, 0) or [1, )
Brackets [ ] include the endpoints.
Parentheses ( ) do not include endpoints.
Set-Builder Notation: {x  2  x  0 or x  1}
Read this as “x such that”
This set cannot be described in roster notation because you cannot list
the real numbers in the intervals shown on the number line.
The roster notation of
, the set of natural numbers, is {1, 2, 3, ...}.
is {xx 
The set-builder notation of
}.
Rewrite each set using the indicated notation.
4. the set of integers, or
; roster notation {, 3, 2,_______________________________}
5. {0, 4, 8, 12, 16, }; words
______________________________
6. 5  x  12; interval notation
[ _______________________________
7. {xx  0}; interval notation
( _______________________________
8.
set-builder notation
{x _______________________________
Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor.
1-7
Holt Algebra 2