Add and Subtract Decimals to the hundredths place using concrete and pictorial models

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Add and Subtract Decimals to the hundredths
place using concrete and pictorial models
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Subtraction

• What is subtraction?
• -the act of finding the difference between two
  numbers
• -the inverse, or opposite, of addition

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Subtraction

• There are three types of subtraction problems
• Take away
• How many more are needed
• Comparison

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Take Away

• Jason counted 8 blue jays at the bird feeder.
  Three flew away. How many are left?

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Take Away

• Jason counted 8 blue jays at the bird feeder.
  Three flew away. How many are left?

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How many more are needed

• Jennifer wants to buy a 20-cent (0.20) candy bar.
  She has 12 cents (0.12). How much more does she
  need to buy the candy bar?

20
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How many more are needed

• 12 ? 20 or 0.12 ?0.20

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Comparison

• Shelly has 6 shells in her collection. Bob has 4
  shells in his collection. How many more shells
  does Shelly have than Bob?

Bob
Shelly
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Comparison

• Shelly has 6 shells in her collection. Bob has 4
  shells in his collection. How many more shells
  does Shelly have than Bob?

Shelly
Bob
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Subtracting
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Subtracting with Decimals
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Adding Subtracting with Decimals

• Line up decimals
• Add zero as a place holder (equivalent decimals
  0.7 0.70

1.2 2.25
1.20 2.25
10.25 - 9.50
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Guided Practice

• 2,000-699

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2. 2.25-1.10
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3. 2.25 1.85

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4. Tanya bought some apples for 1.65. She gave
the clerk 2.00. How much change should she get
back?
-
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5. 0.7 0.25
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