Pascal's Triangle

Pascal's Triangle is a special pattern made of numbers. The numbers are stacked in the shape of a triangle. Each row starts and ends with the number 1. To find the other numbers, you add the two numbers just above them. It looks simple, but it hides many amazing secrets!

How to Build It

Start with a 1 at the top. Below it, write two 1s. For the next row, put a 1 on each end. In the middle, add the two numbers from the row above. Keep going as long as you like. The triangle can grow forever!

Watch each number appear by adding the two numbers right above it.
Watch each number appear by adding the two numbers right above it. (Hersfold / Wikimedia Commons)

Cool Patterns Inside

Pascal's Triangle is full of fun patterns. Each row adds up to a power of 2. You can find counting numbers along one line. You can even find triangle numbers in another line. Some people color the odd numbers and see a pretty shape appear.

Fun Facts

  • The triangle is named after a French math guy named Blaise Pascal.
  • People in China and India knew about it long before Pascal did.
  • If you color all the odd numbers, you get a shape called the Sierpinski triangle.

Did You Know?

Pascal's Triangle can help you figure out how many ways you can pick things from a group, like choosing ice cream flavors!