# Equations and Formulae

This collection of STEM resources is based around equations and formulae.  Resources are listed in order of stage.

### Temperature

##### Stage: 3 Challenge Level:

Water freezes at 0°Celsius (32°Fahrenheit) and boils at 100°C (212°Fahrenheit). Is there a temperature at which Celsius and Fahrenheit readings are the same?

### Using the Haemocytometer

##### Stage: 4 Challenge Level:

Practise your skills of proportional reasoning with this interactive haemocytometer.

### Back Fitter

##### Stage: 4 Challenge Level:

10 graphs of experimental data are given. Can you use a spreadsheet to find algebraic graphs which match them closely, and thus discover the formulae most likely to govern the underlying processes?

### Constantly Changing

##### Stage: 4 Challenge Level:

Many physical constants are only known to a certain accuracy. Explore the numerical error bounds in the mass of water and its constituents.

### How Do You React?

##### Stage: 4 Challenge Level:

To investigate the relationship between the distance the ruler drops and the time taken, we need to do some mathematical modelling...

### Electric Kettle

##### Stage: 4 Challenge Level:

Explore the relationship between resistance and temperature

### Construct the Solar System

##### Stage: 4 and 5 Challenge Level:

Make an accurate diagram of the solar system and explore the concept of a grand conjunction.