The first thing you need is the right kind of measuring tool. Scientists always use the metric system, so you’ll need a metric ruler. Most measuring tapes that you have around the house probably measure in inches and feet only! These measurement devices will not work for this activity.

If your ruler does not have centimeters on it, you can download the ruler below and print it out yourself.

Just make sure to look closely at your printer settings. Print at 100% scale and do not select “fit to paper” or “printable area”.