Test task implemented using Wicket framework version 7.6.0. It was built with Maven version 3.5.0, Eclipse plugin m2eclipse also, Java version 1.8.0_131. Simple interface based on the wicket markup and styled using pagestyle.css. There is default Start class, which is an entry point for an application. CalculatorPage class contains all the business logic, while CalculatorPage.html is page markup.