Use of HTML:
In this program, we are using HTML to create content for the calculator UI; that means we are creating boxes, input fields, buttons, etc.
Use of CSS:
We are using CSS for managing the content of HTML like the content color, width, height, font size, padding, margin, etc.
Use of JavaScript:
In a calculator, it is established that there are different buttons and all these buttons have different functions. For example, the + button performs the addition operation, and – performs the subtraction, and it is possible to assign these operations to these buttons using JavaScript.