1. Do Now 9/4 Please take your homework (half-sheet) and quiz corrections out and yellow textbook slip if you have not turned it in yet. Copy and Answer: Positive x Positive = ______ Positive x Negative = ______ Negative x Negative =______Negative x Positive = ______ For each problem, guess what the answer will be. Then, check your guess by multiplying it out. 1)(15) x 3 =2) (-11) x (-23) 3) (22) x (-30) = 4) (-13) x (29)

2. Multiplying Decimals Wednesday, September 4 th

3. To multiply decimals, multiply as you would with integers, and then place the decimal point. The product should have the same number of decimal places as the sum of the decimal places in the factors. 7  8 8 56 0.7  8 8 1 decimal place 0 decimal places 1 decimal places + Same digits.

4. -7  8 8 -56 56 -0.7  0.8 1 decimal place 2 decimal places + Same digits -0. Multiply decimals as your normally would, then use our rules from last week to determine if your product should be positive or negative.

5. Multiply. Estimate to check whether the answer is reasonable. Example 1 -3.84  -0.9 2 decimal places 1 decimal place -3.84  (- 0.9) 3.456 2 + 1 = 3 decimal places Estimate -4  (-1) = 4 3.456 is a reasonable answer because it’s close to 4

6. Multiply. Estimate to check whether the answer is reasonable. Example 2 -3.2  1.6 1 decimal place -3.2  1.6 -1 92 1 + 1 = 2 decimal places + (-3 20) -5.12 Estimate -3  2 = -6 -5.12 is a reasonable answer because it’s close to -6.