The world is a strange place. Most of us are aware that when you travel to other countries, you may find different languages, culture, and food, but you would expect that at least numbers and measures would stay the same wherever you go, right? Well, this is not so.

Measures such as distance, speed, weight, volume, and temperature change based on where you live. Actually, there are two main measurement systems in use today: the imperial system, which is used mainly in the United States; and the metric system, which is used in most of the other countries.

In this chapter, you'll bring some order to this confusing world: you will build a measures conversion app, in which distance and weight measures will be converted from imperial to metric, and vice versa.

We'll cover the following aspects in this chapter:

• Project overview
• Understanding state and stateful widgets
• Creating the measure converter project