Your physics text book probably claims that an object will tip and fall over if its center of gravity lies outside the object's base. So how is it possible to shift a card well beyond the base of the stack? ...

A simple yet memorable way to teach fractions with 3 cups and a bit of water.

The Möbius strip and its unusual properties are puzzling if not irritating. It is a very good example that illustrates how fast we leave familiar ground and confront difficulties to truly comprehend what's going on. As simple as its form may seem, ...

It is quite common to see a part of an apple or an orange rocking on a table. This every-day situation offers a good opportunity to introduce or reinforce important concepts of mechanics, such as angular momentum, center of gravity and ...

Maps are projections of a sphere onto two dimensions – they naturally distort size and shapes. By comparing the size of Brazil and Greenland on a map and on a globe, your students will see and understand this effect very clearly.

A simple dice game to exercise mental arithmetic, e.g. if you have to stand in for a colleague in a cover lesson.

The security of the internet largely depends on cryptography algorithms which rely on the difficulty to factorize very large numbers (e.g. RSA). For smaller numbers, on the other hand, it can be fun and might make your students eager to hone their ...

A woman gives birth to fraternal twins: what is the probability that they are a) two girls, b) two boys, or c) a boy and a girl? You might think that the answer is obvious, but surprisingly many people hold on to ...

Humans have a very bad sense for statistics. Our 'feeling', how likely certain events should be, does not always match the statistical reality. Technology, on the other hand, is increasingly shaped by algorithms that decide based on statistics and probabilities. Since these ...

This little game is based on a famous psychology experiment. Researchers demonstrated with it that humans often hold a confirmation bias: We naturally tend to seek evidence that confirms our current believes, rather than to look for evidence that falsifies theories. Karl ...

Often, symmetry is explained with the words 'If you would hold a mirror here,..' So why don't you simply do it? Or even better: let your students do it? ...

Marie and Pierre Curie observed radioactive decay as a glow in their darkened laboratory. It is NOT recommended to repeat this experiment with your students! Instead, let your students explore the law of radioactive decay with a bag of dice. This ...