Sicherman Dice

 These dice have the numbers 1-2-2-3-3-4 and 1-3-4-5-6-8, but give the same sums with the same probabilities as two normal 1-to-6 dice. The only difference is the odd of rolling a double which as usually 6/36 are 4/36 for the Sicherman dice.

Seebeck effect

Thermoelectric generation using a Peltier Module to utilize the Seebeck effect to generate voltage. When heat is applied to one of the two semiconductors, heated electrons flow toward the cooler semiconductor. If the pair is connected through an electrical circuit, direct current flows through that circuit.
 

Cheek cells +

 What are all those little black things with my cheek cells asked a student, looking down the microscope at his freshly prepared cheek cell slide. These are bacteria. He went and brushed his teeth immediately and prepared a new slide.

Wind up Car Racing

 Physics is fun. The students played with wind-up racing cars to investigate energy changes. They came up with all the energy losses on their own, demonstrating the benefits of practical learning over theoretical learning.

Algorithms

 Studying the principles of Algorithm design helps students create faster, more efficient programs that are usually easier to create and debug.

Shapes of Molecules

The shape of the molecule affects the shape of the crystal. Modelling using dice shows how different shapes can and can't fit together and gives rise to the crystal shapes we observe.

 

Lenz's Law

 Demoing Lenz's Law but using the @pascoscientific Metre Stick so the students can see what is happening. It stopped all the argument about slowing down by banging on the side of a copper pipe or becoming stuck or me having another magnet in my hand