Magic Triangle

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Place the digits 1 through 9 in the circles in a very special way.

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The End Digits II

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What are the last two digits of large power of 7?

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The End Digits

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What are the last two digits of a huge number?

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What Number Is It?

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Determine a number given its particular properties.

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Difference of Squares

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Write a given number as the difference of two squares.

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Ending a Perfect Square

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Find a special number that can make other numbers into perfect squares.

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Who Wants to Win One Million?

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Find particular factors that produce 1,000,000.

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Fortune Telling

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Using only a digit and the four basic operations (+, -, x, /), produce a set of numbers.

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Inside a Domain

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Find all the whole numbers that can replace the variable x in a given expression so that the expression has a particular value.

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100 Sums

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Do any numbers from a given set have a sum of 100?

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