Valorie asked me this question today, and I figured I'd toss it out to everyone who runs across this post.

She works in a 5/6 split class, and they're working on a unit on patterns and functions. They're ordering the data into columns, each of which is derived from the information in the previous column.

The question is: What do they label the columns?

The first couple are obvious: Primary, and Secondary.

Third and fourth: Tertiary, Quaternary.

But what's the label for the fifth and subsequent columns?

AskOsford.com suggested that they use quinary (5), senary (6), septenary (7), octonary (8), nonary (9) and denary (10), using the latin roots.

But the teacher in the class remembers a different order and thinks that the next one (5) should be cinquainary (using the same root as the poetry form cinquains).

Valorie also pointed to http://mathforum.com/dr.math/faq/faq.polygon.names.html for a 2-page history lesson. Coolest fact she found: the "gon" part of the word means "knee" and the "hedron" means "seats" so a polygon means "many knees" and polyhedra means "many seats".

So does anyone have any suggestions?