7. Rules For Integers
• When Signs are the same, add the
numbers!
-5 - 1 = 5 + 1
• Answer gets the sign of the
larger number.
5 is the largest number
it’s sign is a (-).
Answer is -6.
8. Rules For Integers
• When Signs are the different
subtract the numbers.
-5 + 1 = 5 - 1
• Answer gets the sign of the
larger number.
5 is the largest number
it’s sign is a (-).
Answer is -4.
9. Let’s Practice
1) 5 - 6 =
2) -3 + 2 =
3) 6 + 5 =
4) -8 + 7 =
5) 9 - 9 =
Remember: If signs are the same add
the numbers, if signs are different
subtract the numbers. Then give the
answer the sign of the largest number!
-1
-1
+11
-1
0
10. Rules for Integers
• When Parenthesis ( ) are involved we
get to doodle!
• This is where you need to draw some
faces. (Bet you didn’t know you’d be
doing Art in Math!)
11. Rules for
Adding & Subtracting
Integers Continued
• When you multiply a (+ x -) you get a (-).
• When you multiply a (- x -) you get a (+).
• When you multiply a (+ x +) you get a (+).
5 + (-1) = 4
5 – (-1) = 6
5 + (+5) = 10
-
+
+
12. Let’s Practice
1) 4 – (-5) =
2) 9 + (-7) =
3) 6 – (+2) =
4) 8 – (-7) =
5) 9 + (+3) =
Remember: DRAW the faces first! If signs are
the same add the numbers, if signs are
different subtract the numbers. Then give the
answer the sign of the largest number!
9
2
6
15
12
+
-
+
-
+
13. Let’s Practice Cont.
1) 5 + (-2) =
2) 3 – (-4) =
3) 1 – (+2) =
4) 5 – (-3) =
5) 7 – (-6) =
Remember: DRAW the faces first! If signs are
the same add the numbers, if signs are
different subtract the numbers. Then give the
answer the sign of the largest number!
-
+
+
-
+
3
7
-1
8
13
14. Rules for
Multiplying Integers (x)
• The product of two integers with the
same signs is POSITIVE.
• The product of two integers with
different signs is NEGATIVE.
15. Rules Summary for
Multiplication
• Positive x Positive = Positive
• Negative x Negative = Positive
• Positive x Negative= Negative
• Negative x Positive = Negative
16. Let’s Practice “Multiplication”
1) 6 x (-3) =
2) 3 x 3 =
3) -4 x 5 =
4) -6 x (-2) =
5) -7 x (-8) =
-18
9
-20
12
56
Remember:
Positive x Positive = Positive
Negative x Negative = Positive
Positive x Negative= Negative
Negative x Positive = Negative
17. Did you know that
the rules for
multiplication and
division are the
same?
19. The rules for division are exactly
the same as those for multiplication.
If we were to take the rules for
multiplication and change the
multiplication signs to division signs,
we would have an accurate set of
rules for division.
20. Rules for
Dividing Integers (÷)
• The quotient of two integers with
the same signs is POSITIVE.
• The quotient of two integers with
different signs is NEGATIVE.
37. ANSWER
• If the signs are the same, your answer is
always positive.
• If the signs are different, your answer is
always negative.
*Multiplication and Division Rules are the
same!
