# Make your own Number Patterns

You can make your own number patterns using coins or matchsticks. Here is an example using coins:

Size=1 | Size=2 | Size=3 | Size=4 |
---|---|---|---|

1 Coin | 6 Coins | 15 Coins | 28 Coins |

How many coins do you need for Size=5 ?

Can you make a formula that will tell you how many coins are needed for any Size? For example Size=20? The formula may look something like

**Coins = Size × Size + ...**

(Note: There are lots of number patterns in Pascal's Triangle)