Download Lesson 5

Lesson 5.1
Integers and Graphing
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November 3, 2014
Integers are whole numbers that describe opposite ideas in mathematics.
Integers can either be negative(-), positive(+) or zero.
The integer zero is neutral. It is neither positive nor negative, but is an integer.
Integers can be represented on a number line, which can help us understand the valve of the integer.
Are to the right of zero
Are valued greater than zero.
Express ideas of up, a gain or a profit.
The sign for a positive integer is (+), however the sign is not always needed.
Meaning +3 is the same value as 3.
Are to the left of zero
Are valued less than zero.
Express ideas of down or a loss.
The sign for a negative integer is (-). This sign is always needed.
Use integers to represent data
Positive whole numbers, their opposites, and zero are called integers. To represent data that are less than a 0,
you can use negative integers. A negative integer is written with a – sign. Data that are greater than zero are
represented by positive integers.
Negative integers
Zero is neither negative nor positive.
Positive integers
Opposites are numbers that are the same distance from zero in opposite
directions.
1) Write an integer for the following situation. Explain the meaning of zero.
a 10-yard loss
Because it represents a loss, the integer is -10. In football, the integer 0 represents no yards lost or no yards
gained.
2) Write an integer for the following situation. Explain the meaning of zero.
4 inches of rain above normal
Because it represents above, the integer is 4. In this situation, the integer 0 represents the normal amount of rain.
3) Write an integer for the following situation. Explain the meaning of zero.
A $48 deposit in a savings account
Because it represents an increase, the integer is 48. In this situation, 0 represents neither a deposit nor a
withdrawal.
Graph integers
Integers and sets of integers can be graphed on a horizontal or vertical number line. To graph a point on
a number line, draw a point on the number line at its location. A set of integers is written using braces,
such as {2, -9, 0}
4) Graph -7 on a number line.
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
2
3
4
5
2
3
4
5
4
5) Graph the set of integers {-4, 2, -1}
Draw a number line. Then draw a dot at the location of each integer.
-5
-4
-3
-2
-1
0
1
6) Graph the set of integers {0, 2, -3} on a number line.
Draw a number line. Then draw a dot on the location of each integer.
-5
-4
-3
-2
-1
0
1
7) Alaina and her dad played golf on four different days. The data set {-1, +1, -3, +2} shows Alaina’s scores in
relation to par. Graph the scores. Explain the meaning of zero in this situation.
Draw a number line. Then draw a dot on the location of each integer.
-5
-4
-3
-2
-1
0
1
2
3
4
5