Math Puzzler: Triangle Sums

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From Prufrock Press’ Advanced Common Core Math Exploration series, we introduce the Triangle Sums exploration.

  1. Using the digits 1-9, and four blanks per side, students try to sum up each side of a triangle to equal 17.
  2. We break down the importance of the corner spots, then students use 1-12 and five blanks per side to sum up to the smallest sides possible.
  3. We reveal the solution, then students try to predict the smallest sides of a triangle with only 3 blanks per side, then 6 and 7.
  4. We discuss the pattern between the sum of all numbers and the sum of the smallest sides.

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