Switch branches/tags
Nothing to show
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
33 lines (27 sloc) 1.7 KB


Calculator to help visualize simple operations


  • Written by Pius Wong,
  • Originally part of a FreeCodeCamp exercise in HTML/CSS/JavaScript
  • Created Sep 19, 2017
  • Modified through Jan 2018


This web app is meant to be a basic visual calculator that allows users to add, subtract, multiply, and divide numbers by pressing the appropriate buttons, just like a real, physical calculator. Another button will clear the screen. In addition, this app should also help users envision these operations on individual units or objects. I hope it helps people of all ages understand how to manipulate numbers better and attach meaning to these operations.

Known Bugs

These are known bugs that should be fixed over time. They haven't been fixed yet due to being lower priorities:

  • Division animations not yet completed
  • Browser compatibility:
    • Firefox, Edge (1/30/18):
      • Fractions/decimals don't show up correctly.
      • Multiplication/squaring has squashed units during animation.
    • IE (1/30/18):
      • Multiplication/squaring doesn't appear at all.
    • Chrome is OK (1/29/18).
    • Is Safari OK?

Desired Additional Features

  • Choice of color scheme for positive and negative numbers
  • Controller for animation speeds
  • Negative sign should be applicable before number presses (this may require large coding changes)
  • Alternate subtraction animation? If both numbers are the same sign, just take units them away. (Maybe give option)


*The original project was named "Calculator Alligator" before I found out that a children's book already existed by that name. I've changed it to "Calculator Gator" to disambiguate the names and because it is easier to say.