Measuring length

Remember that the SI unit for length (l) is the metre (m). Another very important thing to remember about measurement-and about scientific method in general- is that you need to be very clear about what exactly it is that you are measuring.

For example, if you measure the height of a door, do you measure the distance from the floor to the top of the door itself (the part that opens) or do you measure from the floor to the top of the door frame?

It doesn't matter what you measure, but it is important to be quite clear about what it is that you measure. In the scientific method, there should never be any doubt about exactly what has been done or exactly what has been measured.  

Measuring distance

To measure short distances, you can easily make a metre rule out of wood or bamboo. You can use stiff cardboard for shorter rulers, but cardboard is not suitable for making a long ruler.