Guess and Check

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Guess and Check

• Problem Solving Strategy

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Guess and Check

• Guess and check is one of the most used and most
  useful problem-solving strategies. The name
  doesnt seem to offer credibility to this
  strategy. Guess and check often feels like
  cheating, but it isnt.
• Golfers often had their balls land in sand
  hazards but someone figured out that using a sand
  wedge is a great way to escape a sand trap
  (problem solved at least sometimes!). It was
  once thought of cheating by some people, but now
  sand wedges are an acceptable part of the game.
• Guess and check is not only a strategy, it is an
  attitude. When using this strategy, you are
  showing your confidence in being able to solve
  the problem even if you dont really understand
  it in the beginning. Then through your
  organization and persistence, you will work
  toward a solution.

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Guess and Check

• Guess and check is very effective in giving you a
  place to start when you tackle a problem. Often,
  guess and check will allow you to eventually find
  a way to set up an algebraic equation to help
  speed up the process.
• Guess and check isnt always the most efficient
  way to solve a problem in some problems unless
  you know how to organize your work and know how
  to work with it, but can be a powerful way to
  find a solution if you know how to use it
  correctly.

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Guess and Check

• Things to remember about guess and check
• Start guessing. As you work through a guess,
  youll learn something about the problem.
• Keep your work organized. You will not get
  anywhere if your work is not organized.
• Be ready to start over. As you learn more by
  working through your guesses, you may discover
  that your first approach was not productive.
• Start with smaller numbers and build up to bigger
  numbers. Make your guesses skip around so you
  can isolate the right answer.
• Sometimes rate your guesses. Is it a good guess?
  Is it better than the last one or not as good.
• Pay attention.
• Avoid arithmetic mistakes.
• Put a lot of information in your column titles so
  that you know what each column represents. Be
  descriptive.

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Guess and Check

• Guess and check is often called testing the
  hypotheses in the sciences.
• Musicians use guess and check when they determine
  how much to tighten or loosen the strings on
  their instruments to meet a target pitch,
  refining each guess to reach the goal.

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Cascade Park Waterfall

• As Crystal looked up at the waterfall, she said,
  Wow, I think the top of that fall is about 20
  feet more than three times the height of that
  young redwood! Margie said, No, I think its
  about 50 feet less than four times the height of
  the redwood. If both are approximately right,
  about how tall is the redwood and how high is the
  waterfall?

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Start a guess-and-check chart.
Put a lot of information in the column titles.
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Be ready to start over.
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Build from smaller to bigger numbers.
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Bracket to close in on an answer.
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Strategy Guess and check

• Start a guess-and-check chart.
• Be ready to start over.
• Build from smaller to bigger numbers.
• Bracket to close in on an answer.
• Be careful to rate guesses correctly.
• Avoid arithmetic mistakes.

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Now, its your turn

• Open your problem solving book and go to the
  section on Guess and Check (pages 15-16).
• Print off a problem solving sheet and do a
  complete solution to a problem from this
  sectiondo one and submit it or do more for
  extra fun. (Cascade Park Waterfall,
  Refinancing, and/or Cell Phone Plans)
• Email your complete solution, with your steps
  clearly shown to NCAMath_at_district87.org or put
  them in Nancy Powells mail box!
• Have fun and Problem solve!