Math Puzzles and Paradoxes
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Math Worksheets
Wrapping a Rope around the Earth Puzzle
Suppose Poindexter takes a very long rope and wraps it around the equator of the Earth. Assume he has just the right length that makes this work without any slack. Suppose Alistair then comes along and adds 10 feet of rope to the length and the tiny bit of slack is used to have the rope uniformly hover just ever so slightly above the ground. How high off the ground is that rope?
Let's answer this puzzle in one fell swoop for ALL planets, not matter their size, and answer it for cubical planets and triangular planets as well!
Dots on a Circle Puzzle
This seemingly straightforward activity leads to astoundingly surprising discoveries. For starters, patterns, no matter how compelling they may seem, need not always be true! This puzzle proves this.
Bertrand's Paradox
In the late 1800s French mathematician Bertrand proposed a disturbing paradox which seems to lead one to think that one third equals one half which equals one quarter. It shook the foundations of probability theory.
Let's examine - and explain - the paradox!
A Harmonic Series Paradox
Here's a cute, but disturbing, geometric interpretation of two famous series in mathematics: the harmonic series (which sums to an infinite value) and the Basel series (which sums to a finite value). Put the two together and ... WHOA!
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Fact Family Game:
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Number Bond Garden:
Clear the board by matching number pairs that sum to ten in this garden-themed mental math puzzle.