Homework help - root words of numbers

[oftengrumpy]

Hi I've been trying to help DS with his literacy homework but I have to own up - I'm stuck too! He has to find the root words of some numbers (words derived from them). He's been given 2 - root word two, 3 root word tri and 4 root word quart as examples but has to find some more. Any ideas anyone?

uni-one, quin-five, oct-eight, deca-ten, sex-six, sept-seven

My DS had this homework over the weekend!

do you mean like oct- ?

5 - pent eg, pentangle

6 - sex - eg, sextuplets, sextant

7 - hept -eg, heptathlon

8 - oct - eg; octagon, octopus

9 - non - eg; nonagenarian

10 - dec - eg; decathlon, decimal

Hope I've understood that correctly.

Bi is also one for two - bicycle, binary etc

pent for 5

hex for 6

hept or sept for 7

oct for 8

non for 9

dec for 10

Semi interesting fact - calendar used to start at march and so September was the 7th month, October the 8th month etc. I think July and August had different names although can't remember what they were, but they were renamed after Julius Caesar and Augustus Caesar.

Surely the root meaning two is bi ?

Have just learned what a pentangle is. Was thinking it was a typo for a pentagon and discovered it is a five pointed star. I do like learning new things :)

Thanks everyone. I though two was bi but, with the help of google, I've decided that bi is prefix for two not the root? Thanks LizzyLiz we'll copy share your DS's answers!

some are from latin and some are from greek. octa is from both latin and greek. I can not remember the rest. they are in one of the maths books I bought to help dd. intended for use in a couple of years time, but she has found it and asked me to read this section a couple of times. shows how little attention i was paying.