Making cardboard dice is a fun and easy paper craft project. All the folds are 90-degree angles, and there are no complex overlapping folds as in origami. The only difficult thing is getting a die that is true. If your folds or cuts are uneven, you can make a die that favors one side over the other, resulting in bad rolls. Take your time and you should come up with a true die.
Things You'll Need
Get a nice piece of cardboard. You don't want thick corrugated cardboard, but something thin and stiff. Card stock will work well, as will a cereal box.
Decide on the size of dice you want. The bigger they are, the easier they will be to make. The piece of cardboard needs to be more than 4 times as long and 3 times as wide as the dice you are making.
Download plans for foldable dice, such as those linked to below in the Resources section. There are many different possible ways to expand a foldable cube, so don't be surprised if you find another version that looks quite different.
Consider using a graphics program to resize the image to the size you want. The bigger it is, the easier it will be to fold. So if your kids are folding dice, you might want to enlarge the design first.
Print out the design and glue it to your cardboard with a very thin layer of white glue. if you are using card stock, try printing the design directly on it, since this will give you better results.
Cut out the design. A craft knife will probably give you the best results, but a pair of scissors should also work well.
Fold and glue the design. Make every fold at a 90-degree angle and tuck the tabs behind the edges. Anchor them with a small dab of white glue.
You may want to score the edges to make it fold easier--particularly if you are using thicker cardboard. Use a craft knife to make a shallow cut at each edge.
Be careful how you glue the die. Using too much glue or gluing it unevenly can result in a weighted die which heavily favors one side.