1. Warm-up Check homework Odds w/book Evens with a neighbor
“We cannot hold a torch to light another’s path without brightening our own.” – Ben Sweetland
Check homework
Odds w/book
Evens with a neighbor
Sections 2.1 – 2.4
No more than 5 minutes!
Warm-up

2. 2.5 Multiplication of Integers
Properties of Multiplication
a * b = b * a
The order of 2 numbers being multiplied does not matter.
1 * a = a
The product of one & a number is that number.
0 * a = 0
The product of zero & a number is zero.

3. The product of a number and -1 is the opposite of that number.
-1 * a = -a
The product of a number and -1 is the opposite of that number.
a * -b = -ab
The product of a and –b is the opposite of ab. Multiplying 2 numbers with different signs is ALWAYS a negative answer.
-a * - b = ab
The product of –a and –b is ab. Multiplying 2 numbers with the same sign is ALWAYS a positive answer.

4. examples
-3 * -2 * -4 =
-4 * x * -12 =
(-x)3 =
(-x)2 =
(-2)4 =
-24 =

5. Sect. 7 – Division of Real #
The integer rules for division are the same as for multiplication.
Same signs = positive answer
-20/-4 = 5
Different signs = negative answer
-20/4 = -5

6. Division can be written as multiplication.
Reciprocals – numbers when multiplied together equal 1 (excluding 1 * 1)
Reciprocal of a/b is b/a
Reciprocal of 4 is ¼
Division w/reciprocals
To divide “a” by “b”, you can multiply by the reciprocal of “b” and get the same answer.
20/4 is the same as 20 * 1/4

7. Write the division as multiplication & solve
3/5 divided by 2 =
3/5 * ½ =
3/10
3x divided by 1/3 =
3x * 3 = 9x
-x / (-6) =
-x * (-1/6) = x/6

8. Simplifying a quotient
Change to multiplication (32x – 8)/4 =
(32x – 8) ¼ =
¼(32x) – ¼(8) =
8x – 2
(32x – 8)/4 = (another easy way)
32x/4 – 8/4 =
8x - 2

9. Try these
6/7 divided by 3 =
6/21
4x divided by 3 =
4x/3
(12x + 28)/4 =
3x + 7

10. Questions?
Mid-chp quiz tomorrow
Need to see some of you