Multiplying Negative and Positive Numbers Problem 3.1 Multiplying Positive and Negative Numbers

Multiplying Negative and Positive Numbers

In a far off place.... A team of amazing chef’s are cooking a marvelous meal of stew. For each hot cube added to the pot, the temperature raises one degree. Similarly, each cold cube added to the pot will lower the temperature one degree.

Multiplying Negative and Positive Numbers An example: If the chef added 3 hot cubes and then removed 2 cold cubes, the combined result would raise the temperature 5˚. –Number sentence 3 - – 2 = 5

Multiplying Negative and Positive Numbers Warm up... 1.Add 8 cold cubes and add 4 hot cubes. Write a number sentence What is the new temperature? 2.Add 12 hot cubes and remove 7 cold cubes. Write a number sentence What is the new temperature?

Multiplying Negative and Positive Numbers Multiplication There are many symbols to represent multiplication –Examples

Multiplying Negative and Positive Numbers For large jumps in temperature Now the chef’s are adding and removing large bunches of cubes. For example, if the chef’s wanted to raise the temperature 100˚, they would add 5 BUNCHES of 20 hot cubes. –This makes the process go much faster.

Multiplying Negative and Positive Numbers The number sentence Add 5 BUNCHES of 20 hot cubes Number sentence

Multiplying Negative and Positive Numbers Multiplication Example: 1. The chef wants the temperature to raise 75˚ –How many bunches of 25 hot cubes will he need to add to the stew? 2. The chef wants the temperature to decrease 100˚ –How many bunches of 10 hot cubes will he need to remove?

Multiplying Negative and Positive Numbers More examples: 3. The chef wants the temperature to decrease 15˚ –How many bunches of 5 cold cubes will he need to add to the stew? 4. The chef wants the temperature to increase 40˚ –How many bunches of 8 cold cubes will he need to remove? –Now continue to answer questions on the back side of your worksheet.

Multiplying Negative and Positive Numbers Solve each problem

Multiplying Negative and Positive Numbers Solve each problem

Multiplying Negative and Positive Numbers Solve each problem

Multiplying Negative and Positive Numbers Commutative? Is multiplication commutative?

Multiplying Negative and Positive Numbers

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