Students learn how to work out the equation of a straight line graph.

Later, as learning progresses students consider negative, as well as positive gradients.

**Differentiated Learning Objectives**

- All students should be able to derive the equation of a positive straight line graph in the form y = mx + c
- Most students should be able to derive the equation of a straight line graph in the form y = mx + c
- Some students should be able to derive the equation of a straight line graph using two pairs of coordinates.