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copyright©amberpasillas2010
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For Learning to Happen! Take out a piece of paper. Take out something to write with. Try all of the examples. Ignore all other distractions. Watch the 1 st slide then I will have you try a few examples.
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copyright©amberpasillas2010 1 1 = +1 1 -1 = -1 -1 -1 = +1 -1 -1 -1 = -1 Odd # of Negatives = Negative Even # of Negatives = Positive -1 -1 = +1
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copyright©amberpasillas2010 1) 0.16 x 30 000 08 + 4 08 4 1 2) 70 x 1.2 041 00 7 04 8 + 3) 1 0.0048 x 32 690 0 44 6 3 5 1 1 1 2 0 0 1 + 0 Try these on your paper!
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copyright©amberpasillas2010 Multiply (-3) (-0.14) 2 Step 1: Write the problem vertically 0.14 x 3 Step 2: Ignore the decimal points and multiply Step 3: Determine where the decimal point goes in the product. 1 40 0.42 –. – = + Step 4: Determine the sign of your answer using your integer rules. The answer is POSITIVE
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copyright©amberpasillas2010 Multiply (-0.4) (0.6) 4 0.4 x 0.6 The decimal moves two places to the left 20 – 0. 24 Signs are the same Signs are different POSITIVE NEGATIVE
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copyright©amberpasillas2010 Multiply (0.8) (-0.9) 2 0.8 x 0.9 The decimal moves two places to the left 70 – 0. 72 Signs are the same Signs are different POSITIVE NEGATIVE
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copyright©amberpasillas2010 HOW MANY DECIMAL PLACES? 1 decimal place 3.0 2) (-0.40)(-2.0) 0.40 2.0 1) -3.0(0.20) 0.800 0.20 2 decimal places 0.600 1 + 2 = 3 decimal places 2 decimal place 1 decimal places 2 + 1 = 3 decimal places
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copyright©amberpasillas2010 3.0 2) (-0.40)(-2.0) 0.40 2.0 1) -3.0(0.20) 0.800 0.20 0.600 WHAT IS THE SIGN OF YOUR ANSWER? NEGATIVE POSITIVE
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copyright©amberpasillas2010 Find the product. (-2.8)(-3) -2.8 -3 8.4 POSITIVE
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copyright©amberpasillas2010 Divide 0.27 -3 3 0. 27. 0 0 27 9 27 0 Step 2: Move the decimal point in the dividend straight up into the quotient Step 3: Divide as usual. Step 1: Write the problem in the long division format. Ignore the negatives. TRICK: Dead Monkeys Smell Bad ! = -0. 09 Step 4: Determine the sign.
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copyright©amberpasillas2010 Divide -0.65 5 5 0. 65. 1 0 5 15 3 15 0 Step 2: Move the decimal point in the dividend straight up into the quotient Step 3: Divide as usual. Step 1: Write the problem in the long division format. Ignore the negatives. TRICK: Dead Monkeys Smell Bad ! = -0. 13 Step 4: Determine the sign.
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copyright©amberpasillas2010
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Multiply Negative Decimals Multiply (-0.3) (0.9) 7 0.3 x 0.9 The decimal moves two places to the left. 20 – 0. 27 #10 Signs are the same Signs are different POSITIVE NEGATIVE
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copyright©amberpasillas2010 Divide Negative Decimals Divide (- 0.75) (0.15) 015 0 75. 0 0 0 75 5 75 0.... #11 + + = + – – = + + – = – – + = – Signs are the same Signs are different POSITIVE NEGATIVE = – 5
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copyright©amberpasillas2010 Extras
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copyright©amberpasillas2010 0-2.0 -1.5 -0.5 1.50.5 1.02.0 NegativePositive 0.5 > -2 < 1.5 # < Less than > Greater than
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copyright©amberpasillas2010 + + = + – – = + + – = – – + = – Signs are the same Signs are different POSITIVE NEGATIVE
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