1. 2.1 Day 3: Multiplying more than two integers
Go Math

2. Multiplying Many Integers
When multiplying many integers, you can multiply from left to right
For example,
3(-4)(-2)
Do the first two numbers
(-12)(-2) 24

3. Simplify
-1 (-1) 1

4. Simplify
-1(-1)(-1) 1(-1) -1

5. -1(-1)(-1)(-1) 1(-1)(-1) -1(-1) 1
Simplify
-1(-1)(-1)(-1) 1(-1)(-1) -1(-1) 1

6. -1(-1)(-1)(-1)(-1) 1(-1)(-1)(-1) -1(-1)(-1) 1(-1) -1
Simplify
-1(-1)(-1)(-1)(-1) 1(-1)(-1)(-1) -1(-1)(-1) 1(-1) -1

7. Simplify
-1(-1)(-1)(-1)(-1)(-1) 1(-1)(-1)(-1)(-1) -1(-1)(-1)(-1) 1(-1)(-1) -1(-1) 1

8. See a Pattern??
What is the sign when there is an even number of negative signs? Positive

9. See a Pattern?
What is the sign when there are an odd number of negative signs? Negative

10. Rule: When multiplying Integers,
If there is an even number of negative factors the product is positive
If there is an odd number of negative factors the product is negative

11. Tell whether the answer is positive or negative
3(2)(-3) Negative 3(-2)(-3) Positive
3(2)(-3)(4)(-1)
Positive
5(8)(-4)(2)(-3)(-4)
Negative

12. 285(1) 285 Try these: Multiply 1.) 15(-9) (-1) Answer will be positive
2.) -3 (-6)(-2) Answer will be negative 18(2) -36

13. Homework
Worksheet