Subtracting Integers

Subtracting Integers

"I can subtract integers using chips and number lines."

​Let's Review Adding Integers!

Keep the sign and add their absolute values

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-5 + -7 = -12

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5 + 7 = 12​

Same Signs

Multiple Choice

Evaluate -50 + -25

• 75

• -75

• 25

• -25

​Let's Review Adding Integers!

Determine which number has the biggest absolute value. That will be the sign of your final answer. Then, subtract the absolute values of your integers.​

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12 + -7 = 5

-15 + 10 = -5

-20 + 10 = -10​

Different Signs

Multiple Choice

Evaluate -6 + 8

• -14

• 14

• 2

• -2

Now Let's Learn How to

Subtract Integers!

• Keep the sign of the first number.

• Change the subtraction sign to an addition sign.

• Change the sign of the last number to its opposite.​

• Follow the addition rules.

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-10 - 5 ----> -10 + -5 = -15​

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Keep Change Opposite -----> KCO

Subtraction is the Adding the Opposite.

​Let's try these together....

1) 6 - 9

​

2) -9 - 4

​

3) -8 - 10​

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Keep Change Opposite -----> KCO

Multiple Choice

How do you rewrite 6 - 12 using KCO?

• -6 - 12

• 6 + -12

• 6 - -12

• -6 - -12

Multiple Choice

Now evaluate 6 - 12

• 18

• -18

• 6

• -6

Multiple Choice

Evaluate 5 - 7

• 2

• -2

• 12

• -12

Subtracting a Negative is like Adding a Positive

​If it's getting less cold, it's warming up.

If you are getting less negative, you are getting more positive.​

If you owe less money, you are increasing in wealth.​

​10 - -2​ ----> 10 + + 2 = 12

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Subtracting a Negative is like Adding a Positive

​Let's try these together...

1) 9 - - 10

​

2) -5 - -4

​

3) -8 - -12​

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Keep Change Opposite -----> KCO

Multiple Choice

How would you rewrite 9 - -3 using KCO?

• 9 - 3

• -9 - 3

• 9 + + 3

• -9 + 3

You are on a hike 120 feet above sea level. Your camping site is at 10 feet below sea level. How far apart are you from your camping site? Draw a picture/number line to help you think through this situation.

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120 - -10 = ​

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​Real World Problem