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

Maths Equipment

Attempting to get all the students to have to hand all the basic Maths Equipment that they may need, A calculator, decent compass, 360 protractor, tracing paper pencils and rubber. Some come better equipped but most fail to have all the basics.
 

Magneticforces in a wire

Measuring the magnetic field forces in a wire using an electronic balance with different voltages and recording the orientation of the field according to the electronic flow.