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Adding Integers

Pre-Algebra

Unit 2 Lesson 3

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What is an integer?

Integers: All whole numbers and its opposite

-45

1.25

100

2/5

-12.

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Adding

+ =apple apple MORE apples

+ =fart fart Dangerous Gasses!

(MORE farts)

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Adding Integers with the same sign:

Rule: Same sign, add all together, keep sign.

Try these problems with the chips:

2 + 7 =

-3 + -3 =

-5 + -1 = 6 + 4 =

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Adding Integers with the same sign:

Write out these problems on paper using + and - symbols:

-3 + (-4) = -8 + (-2) = 3 + 7 = example

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Adding Integers with different signs:

Rule: Different sign, find difference, take sign of higher number.

-3 + 9 8 + (-10)

Try these problems with the chips:

5 + (-2) =-6 + 4 =

(-10) + 10 =

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Adding Integers with different signs:

Right out these problems on paper using + and - symbols:

7 + (-8) = -4 + 10 = 3 + (-6) =

SMOTD

example

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Absolute Value: Distance from that number to zero

-1 0-2-3-4-5 1 2 3 4 5

-5 + |-10|

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Integer Jan Ken Po

(rock paper scissors)

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Subtracting Integers

Unit 2 Lesson 4

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Subtraction = "adding the opposite"

6 - 4 can be seen as... 6 + (-4)

5 - 10 can be seen as... 5 + (-10)

-2 - 7 can be seen as...

-9 - 3 can be seen as...

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The "-" symbol has three meanings, what are they?

---

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8 - (-7) can be seen as...

-15 - -2 can be seen as...

-4 - - 4 can be seen as...

Do these problems:

5 - - 10

-3 - 8

-7 - - 6