The graph is a natural cubic spline passing at the outset through 11 points. The points are added as needed whenever you attempt to drag the graph in-between the existing points.
http://www.cut-the-knot.org/Curriculum/Calculus/CubicSpline.shtml
he numbers from 1 through 27 are displayed below in three rows of nine numbers each. Select one of those numbers and reply truthfully to three computer queries.
http://www.cut-the-knot.org/Curriculum/Magic/GergonneMagic.shtml
A farmer is to ferry across a river a goat, a cabbage, and a wolf. Besides the farmer himself, the boat allows him to carry only one of them at a time.
http://www.cut-the-knot.org/ctk/GoatCabbageWolf.shtml
A right triangle with legs 13 and 5 can be cut into two triangles (legs 8, 3 and 5, 2, respectively).
http://www.cut-the-knot.org/Curriculum/Fallacies/CurryParadox.shtml
To make the paradox work for small values (3, 4, 5) of the parameter, check the "Cheat" box. For greater values, the effect is virtually imperceptible.
http://www.cut-the-knot.org/Curriculum/Fallacies/LangmanParadox.shtml
Place three distinct objects in a line. Any three distinct objects will do the job.
http://www.cut-the-knot.org/Curriculum/Magic/MindReader.shtml
When it comes to counting, there is a gap between finite and infinite.
http://www.cut-the-knot.org/Probability/infinity.shtml
Josephus Flavius was a famous Jewish historian of the first century at the time of the Second Temple destruction.
http://www.cut-the-knot.org/recurrence/flavius.shtml
Lagrange interpolation is a way to pass a polynomial of degree N-1 through N points.
http://www.cut-the-knot.org/Curriculum/Calculus/LagrangeInterpolation.shtml
Mastermind is a game played by two players, the codemaker and the codebreaker.
http://www.cut-the-knot.org/Curriculum/Games/MastermindVariant.shtml