Multiplying negative numbers

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

Multiplying negative numbers

-4 + -4 + -4 =
-4 • 3=

1. -12
2. 12
3. 8
4. 8

-5 + -5 + -5 + -5 =
-5 • 4 =

1. 20
2. -20
3. -10
4. 10

Multiplying

• You already know: 4 + 4 + 4 = 3 • 4 = 12
• That's why: -4 + -4 + -4 = 3 • -4 = -12
• These are the rules of multiplying negative numbers:
• positive • positive = positive
• positive • negative = negative
• negative • positive = negative
• negative • negative = positive

7 • -4 =

1. -28
2. 28

-8 • 5 =

1. 40
2. -40

-6 • -3 =

1. 18
2. -18

7 • -8 =

3 • 4 • -12 • 0 • 7 =

Is the result of the following sum
+ or -?
5 • 300 • -2 • -24 • 6 • -32

1. +
2. -