The very image and text used in the article implies that the original poster is correct.
Look at the example for 32 - it is given as 8 + 2x12. The hand on the right has two fingers extended. Clearly all fingers can be extended in this image, and then the number would be 8 + 5x12 = 68. If the left hand is used to count to 12, the number is 12 + 5x12, or 12+60=72.
Either the limit is 60, or the images/text in the article are wrong.
You're right! I didn't look closely enough. You can indeed symbolize 72 with the method shown in the picture.
Now that I finally get what viggity was saying however, I think that what you can count to with two hands wasn't what was significant -- it was that a full, open hand was worth 60.
Look at the example for 32 - it is given as 8 + 2x12. The hand on the right has two fingers extended. Clearly all fingers can be extended in this image, and then the number would be 8 + 5x12 = 68. If the left hand is used to count to 12, the number is 12 + 5x12, or 12+60=72.
Either the limit is 60, or the images/text in the article are wrong.