Group of

Gei is a prefix particle that means 'group of'. It functions similarly to yei and tei. It's most commonly used in numbers. For example geitu is a twosome or a couple; geivi is a threesome; geisa is a foursome; geixotu is a dozen; etc etc.

Gei can also be used in other ways!

Geikomodenusa - A litter of kittens
Geihakaxasa - A circle of friends
Geibiho[muka]sa - Cattle
Geixudosa - A school of fish

A plural is always required when gei- is being used with a non-number word, generally a noun. -Sa is most common, but if we want to draw attention to the individuals in the group being different we can use -sai.

Geihemodosai - A group of unique individuals (people)
Geixudosai - A school of fishes

Numbers beyond counting

We covered counting in another post. Now we are going to go over some other things we need the number words for.

Ordinal Numbers - First, second, third, etc
We simply add 'tei' in front of the number. So first is teia, second is teitu, third is teivi, etc.

Once, twice, thrice
We simply add 'yei' in front of the number. 'Yei' literally means '[number] of times'. So yeiha is once, yeitu is second, yeivi is thrice, yeisa is four times, etc.

Fractions
To form fractions we use 'fe'. So afetu is half, afesa is quarter, etc. For less common, or larger fractions there is often hyphenation when the word is written out. This makes it easier to read. 9/16 for example would be nai-fexode.

You could also use the fraction construction to mean percent. Such as:
I am 100% better!
      Ei hola akugo haku-fehaku!

Counting

Reisu uses a decimal, or base 10 system. The first 10 numbers are as follows.

1	A	6	De
2	Tu	7	Je
3	Vi	8	Ji
4	Sa	9	Nai
5	To	10	Xo

Easy enough, and counting higher than 10 has a fairly regular pattern.

11	Xoa	21	Tuxoa
12	Xotu	22	Tuxotu
13	Xovi	50	Toxo
20	Tuxo	99	Naixonai

Xoa for eleven is simply ten plus one, and so on until you get to 19, Xonai. Once you get to the twenties you use a slightly different structure. Tuxoa for 21 is two times ten plus one. This continues until you get to ninety-nine, naixonai.

100 has it's own name, haku, but structure remains relatively the same.

101	Hakua	211	Tuhakuxoa
102	Hakutu	232	Tuhakuvixotu
103	Hakuvi	500	Tohaku
200	Tuhaku	999	Naihakunaixonai

Once you get to numbers this high sometimes hyphens make it easier to read. For example naihakunaixonai could be written as naihaku-naixonai. This is not required, it simply makes it quicker to read.