Assume that you want to place an order in a different currency and you are looking at a currency exchange web page. Before you place the order you may need to do some calculation. Would it not be nice if such a page had a standard calculator? Similarly, some scientific articles on the Internet require the reader to do some calculation to fully appreciate the topic. Would it not be nice if such a page had a scientific calculator? This is a six-part series which shows you how to design a calculator for your web page.
The Web Page
Your web page will normally have many HTML elements. Here I will talk only about the things related to the calculator on the web page.
It's likely that your web page does not have room for a calculator, taking into account all of the other elements on it. This series starts with that assumption. We will simply put a button with the title "Use Calculator" on our web page. When this button is clicked, the calculator appears. You do your calculation. When you click outside the calculator on the body element, the calculator disappears.