• HTML
• CSS Layout
• Javascript Fundamentals

Now that you're familiar with all the building blocks of a functional web application, let's build something we can really use - a calculator!

Challenge #1.1: Use your knowledge of HTML to create a simple calculator interface. It should contain three text inputs (#num_one, #num_two, and #answer) and four buttons (#add, #subtract, #multiply, #divide). Place your HMTL in a file called index.html, and add some CSS styling in a file called styles.css. Goal #1.1: A simple calculator interface for working with 2 numbers.

Challenge #1.2: Once you're happy with the appearance of your calculator, let's make it work. In a file named main.js, use vanilla javascript methods to link the elements on the page so when a user inserts a number in each input and clicks one of the operand buttons, the result of those numbers & that operand are displayed in #answer. For example, if I type "1" into #num_one and "2" into #num_two, and click on the #add button, #answer should display "3". Be sure to link your Javascript file to your HTML!

Challenge #1.3: It's always good to use source control with our projects. Create a git repository, commit your work and add your repo to Github. Goal #1.3: Submit your Github URL below.

Challenge #2.1: Let's upgrade to a more familiar interface. Refactor your HTML & CSS to imitate the image below. Replace your #num_one and #num_two fields with a single #num_input field, and give each number field an id matching its number (#one, #two, #three, etc). Include an #equals and #clear button, and try to add some CSS transitions to make the process more interactive for users.

Goal #2.1: A redesigned calculator interface.

Challenge #2.2: With an updated interface comes updated logic! Refactor your main.js to work with the new interface. Calculations should only be performed after clicking #equals, and results should be shown in your #num_input field. For this challenge, it's okay to only support two-number expressions (10+3, 25/5, etc). Don't forget to update your Github respository before submitting!

Challenge #3.1: Refactor your Javascript to support any expression length. It's okay to not calculate until #equals is clicked, but be sure your final result handles the entire expression in your input!

• A Github repository containing:
  • index.html
  • styles.css
  • main.js

• Calculator Mockup