Download - 2 3 Subtract Integers
Subtracting Real Numbers
Chapter 2.3
Subtracting is the same as adding a negative!
Warm Up
• What is the opposite of the following?-14 +5.2 -19 19
• What is the absolute value of the following?-14 +5.2 -19 19
• Find the sum-5 + 8= -9 + -12=
Warm Up Answers
• Just change the signs+14 -5.2 +19 -19
• Make them all positive+14 +5.2 +19 +19
• Find the sum-5 + 8= +3 -9 + -12= -21
Subtracting Integers is really adding negatives
• Find the sum 9 + (-6)
• Find the sum 9-(+6)?
• What do you notice about the two number sentences above?
+3
+3
Make a subtraction statement into an addition statement
Exchange the signs in the middle.
4 – (+5) =
-9 – (+8) =
-57 – (+25) =
+87 – (+88)=
A minus sign IS a negative sign.
4 + (-5)
-9 + (-8)
-57 +(-25)+87 + -88
Two negatives make a positive.
4 – (+5) = 4 + (-5)
Opposite
statements
4 – (-5) = 4 + (+5)
Subtract a negative = add a positive.
How do you handle two negative signs in the middle?
-9 – (-8)
Change them both to positive
-9 - (- 8)
-9 + (+8)= -1
Try Some.Rewrite each statement
-57 – (-25)=
-17 – (-21)=
7 – (-13)=
8 – (-33)=
-5 – 15 =
-57 + (+25)
-17 + (+21)
7 + (+13)
8 + (+33)
-5 + -15
And the answer is?
-16 – (-21)=
-83 – (-17)=
83 – (-17)=
47 – (-12)=
-9 – 22 =
-16 + (+21)= -5
-93 + (+17)= -76
83 + (+17)= 100
47 + (+12)= 59
-9 + -22 = -31
pg 71: 23 – 67 odds