Divide Paper into Thirds: Estimation Method

Dividing paper into multiple parts is something that you will need to do when you progress to the intermediate and more advanced origami models. Diving paper in half, quarters, eighths, sixteenths etc. is fairly easy: simply use the edges of the paper to fold the sheet in half, then continue to fold each section in half to get smaller and smaller even-numbered divisions. However, dividing paper into thirds, fifths, sevenths etc can be challenging.

There are many ways to divide a sheet of paper into equal thirds. Some methods are easier than others; the method shown here is fairly easy and is commonly used by many origami artists. This method gives fuzzy crease lines but, for the most part, it is good enough for your basic, non-complex origami model.

This estimation method is called the Fujimoto Approximation Method. The mathematics behind the Fujimoto Approximation is discussed in Tom Hull's book Project Origami: Activities for Exploring Mathematics. You can also learn more about this approximation here.

Divide Paper into Thirds: Estimation Method

  • Take a square sheet of paper and fold it into thirds by estimating or making a "best guess" as to where 1/3 is located. Crease lightly.

  • It is likely that your folds will not be exactly at the 1/3 mark. Re-fold the top and bottom layers of paper by shuffling the paper a little to the right or left as needed.

  • Once this adjustment has been made, the divisions will be closer to the true 1/3 mark. Shuffle the top and bottom layers a second time and refold again.

  • After 2 or 3 iterations, the paper will be divided to 1/3 + 1/3 + 1/3 divisions. Once this has been achieved, crease firmly then unfold. The resulting crease-lines will a little fuzzy: they are not sharp, clean creases. However, for the most part, the creases are good enough to proceed.