## Introduction: DIY Cardboard Counter

I used to play a lot of card games and tabletop RPGs when I was younger. Especially Magic: The Gathering was my favorite. I built a cardboard counter to keep track of my life points. This became very famous among my friends so that I had to build lots of them :)

When I saw the Cardboard Contest I remembered this one and built it once again so I can share it with you guys. You can use it in any game or for any other purpose, where you have to keep track of some numbers (current calendar week, number of days you have the water filter in use, number of workouts or number of kids you have :D). This is a small project and perfect for a rainy afternoon, which you can do with your kids.

I hope you can put this to any use and will enjoy building it. Please post any suggestions in the comments below. Have fun :)

## Step 1: Materials and Tools

You don't need much for this project:
• Small piece of cardboard (colored or plain white)
• Pencil for marking
• Crayons if you want some color :)
• Compasses
• Scissors
• Triangular ruler
• Paperclip

## Step 2: Concept and Some Calculation

The idea is to use two circles which have each the digits 0-9 written on them. Therefore you need to divide the circles into ten equal pieces. I use 2cm and 3cm as radius for the circles. Here comes some math :D

I use the law of sines for general triangles to calculate the width I have to use on my compasses to divide the bigger circle (3cm radius) into ten pieces. Please see the next step for detailed information. You can use the marks on the bigger circle to copy them to the smaller one.

## Step 3: Let's Mark, Fold and Cut

I made one picture for each step. My first approach was to make a GIF, but this turned out to be impracticable. So I turned it into a video on youtube. Now you can easily pause while you follow the steps.

## Step 4: Done

Well that's it. Congratulations, everything is done and you are hopefully a proud owner of a cardboard counter :D