Transcript No Slide Title

Unit 1 Lecture 1
Signed Numbers
Real Number System
Symbols of equality, inequality, less than,
greater than
Unary operations: opposite of; absolute
value
Rules of Addition and Subtraction for
Signed numbers
Mathematical Statement into Symbols
Lecture 1
1
Objectives
• To identify Real numbers
• To learn the rules for addition and
subtraction of signed numbers
• To learn how to go from a mathematical
statements to symbols and solve
Lecture 1
2
Real Numbers
• Two subsets: Rationals and Irrationals
• Rationals contain Integers as a subset
• Integers contain Whole Numbers as a
subset
• Whole numbers contain Counting Numbers
or Natural Numbers as a subset.
Lecture 1
3
Examples
• Counting Numbers or Natural Numbers
{1, 2, 3, . . .}
• Whole Numbers {0, 1, 2, 3 . . .}
• Integers { . . . -3, -2, -1, 0, 1, 2, 3, . . .}
• Rational Numbers { -8, - 1.5, 7/4, 0, 6,
etc.}
• Irrational Numbers {  , 2, 7, etc. }
Lecture 1
4
Lecture 1
5
Addition of Signed Numbers
• Like Signs:
– Ignore the signs
– Add
– Take the common sign
• Unlike Signs:
– Ignore the signs
– Subtract
– Look to see what the sign was of the
larger unsigned number
– Take that sign
Lecture 1
6
Examples
• Like Signs:
+5+3=+8
-5-3 =-8
• Unlike Signs:
+5-3=+2
-5+3=-2
Lecture 1
7
Mathematical Statements into Symbols
1. I have $60 and I owe you $90. What is
my net worth?
+ 60 - 90 =
- 30
Lecture 1
8
Mathematical Statements into Symbols
2. I am in debt for $50 and you give me
$10. What is my net worth?
- 50 + 10 =
- 40
Lecture 1
9
Mathematical Statements into Symbols
3. I am in debt for $30 and you give me
$40. What is my net worth?
- 30 + 40 =
10
Lecture 1
10
Mathematical Statements into Symbols
4. I am in debt for $20 and I owe you
$50. What is my net worth?
- 20 - 50 =
-70
Lecture 1
11
Perform the operation:
–7+5
6 – 10
2 – 11
– 8 – 15
– 6 + 10
1 5

4 6
Lecture 1
12
Perform the operation:
–7+5
–2
6 – 10
–4
2 – 11
–9
– 8 – 15
– 23
– 6 + 10
4
1 5

4 6
1 5 3  10 7
 

4 6
12
12
Lecture 1
13
Subtraction Key
-key, binary key,
7th row, 5th column
Lecture 1
14
Opposite Key
(-) key, unary operation
9th row, 4th column
Lecture 1
15
Use of the calculator to
evaluate – 8.6 + 11.4
To add signed numbers use
the opposite
(-) key, 9th row, 4th column.
– 8.6 + 11.4
is keyed in as
(-), 8.6, +, 11.4, ENTER
2.8
Lecture 1
16
Use the calculator to
evaluate: – 16.85 – 28.42
To add signed numbers use the
opposite key (–) and binary
subtraction key –
– 16.85 – 28.42
is keyed in as
(–), 16.85, –, 28.42,
ENTER
– 45.27
Lecture 1
17