Strategies Using Doubles

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Strategies Using Doubles
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Addition and subtraction with the same partners
is called doubles.

• Addition Doubles Subtraction Doubles

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Odd and Even Doubles

• What do you know about even numbers?

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Odd and Even Doubles

• How can we decide if 6 is an even or odd number?

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Odd and Even Doubles

• How can we decide if 7 is an even or odd number?

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The Doubles Plus 1 and Doubles Minus One
Strategy!

• How might we use doubles to solve this problem?
• 7 6 ___

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7 6 ___

• Using a Double Plus 1 or Using a Double Minus 1

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7 8 ___

• Using a Double Plus 1 or Using a Double Minus 1

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6 5 ___

• Using a Double Plus 1 or Using a Double Minus 1

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8 9 ___

• Using a Double Plus 1 or Using a Double Minus 1

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Lets Practice Two-Step Story Problems

1. Work in pairs.
2. Retell the problem.
3. What do you do first?
4. What do you do second?
5. Show your work. Use a variety of strategies.

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• Aretha has 7 whistles. She has 4 more whistles
  than Jeremy. How many whistles do Aretha and
  Jeremy have altogether?

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• Mina buys 4 shirts and 5 skirts. She returns 2
  skirts to the store. How many new pieces of
  clothing does Mina keep?

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• Ed bought 9 bananas at one fruit stand and 3 at
  another. He bought 8 more bananas than Gail.
  How many did Gail buy?

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• Felix had 7 pounds of white potatoes and 8 pounds
  of red potatoes to cook for the celebration.
  First he cooked 6 pounds. How many pounds of
  potatoes does he still have to cook?

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Extra Practice

• Solve the problems in the first section by
  yourself.
• Then, use the letters for each answer to help you
  solve the riddle.
• If you finish, use the letters on the page to
  create your own riddle. Make sure you number the
  lines for the answer to your riddle correctly.
  Give your riddle to a classmate to solve.