# Interactive Math

## Caesar Cipher

The Caesar Cipher, invented by Roman Emperor Julius Caesar, is a method to send coded messages. Put in your secret message, encode it, and share it with your friends!

Encode your message →## Target Number

In this activity, you'll be given a set of numbers, try to add, subtract, or multiply them to reach the target number!

Find the target number →## Numbers in Art

You've probably learned about the primary colors in your classes, but did you know that all color on the internet is made of numbers? Lean how numbers create color!

Learn about numbers in art →## Tessellation

Some shapes can be fitted together with no gaps is overlaps, while other shapes cannot. Why is this? Visualize tessellation and find out!

Learn how to tessellate →## How Much is One Billion?

You may know how much one hundred is, or even one thousand. But what about one million or one billion? Once the numbers start to get that large, we need to use other ways to visualize it!

Learn how much one billion is →## Math Games

## Nim

Nim is a game where the objective is to take candy, but not the last one. There's a way to always win this game—try to figure it out!

Play Nim →## Nim 2

In this variation on Nim, you want to take the last candy instead. The logic is different from regular Nim, so try to figure it out!

Play Nim 2 →## Water Cups

In this game, you have two buckets and unlimited water. Fill and empty the buckets to get the target amount of water!

Play Water Cups →## Minesweeper

Minesweeper is a game of luck and strategy. You can figure out parts of it and may need to guess for other parts. Take the challenge if you're up for it!

Play Minesweeper →## Card Switching

A game of probability, this will test your knowledge and your luck. Simply decide whether to trade your card for the hidden one, and find out if you win!

Play Card Switching →