Description

This applet shows how a barcode scanner like the ones you see at the supermarket works.

The scanner uses a laser beam to reflect off a series of black and white stripes. The light reflecting from the stripes is read by a sensor that determines the sequence of stripes by the series of flashes of light reflecting from the barcode. By determining the sequence of black and white stripes, the barcode reader is able to convert this code into a number which tells how much your carton of milk costs.

Purpose

Interactive simulation is an excellent tool for showing "how stuff works". The interactive, animated aspect encourages exploration and learning.