Numbers

In general, numbers in Lojban are expressed by reading off the digits from left to right, with a few exceptions. Three zeros can be said ki'o instead of nonono, and there are special words for some powers of ten, which aren't always used.

In some parts, an entirely different system based on hexadecimal is used, though as a foreigner your numbers will probably be understood if you say them in decimal.

Small integers

zerono
onepa
twore
threeci
fourvo
fivemu
sixxa
sevenze
eightbi
nineso
tenpano
elevenpapa
twelvepare
twentyreno
thirtycino
fortyvono
hundredpanono
thousandpanonono / paki'o
millionpaki'oki'o

When counting, you don't say pa, re, ci, as that would be taken as the number 123 said slowly. To separate the numbers, you can say .i pa, .i re, .i ci, or li pa, li re, li ci.

Fractions

one halfpimu / fi'urexadba
one thirdpira'eci / fi'uci
two thirdspira'exa / refi'uci
one fourthpiremu / fi'uvo
three fourthspizemu / cifi'uvo
one seventhpira'epavorebimuze / fi'uze
3+1/7 / 22/7vei cisu'ifi'uze / cipira'epavorebimuze / rerefi'uze

Some powers of 10

10-12piki'oki'oki'oki'opavei gei ni'uparepicti
10-9piki'oki'oki'opavei gei ni'usonanvi
10-6piki'oki'opavei gei ni'uxamikri
10-3piki'opavei gei ni'ucimilti
.01 pinopa centi
.1 pipa decti
100pavei gei nopamei
10 pano dekto
100 panono xecto
103paki'ovei gei cikilto
106paki'oki'ovei gei xamegdo
109paki'oki'oki'ovei gei sogigdo
1012paki'oki'oki'oki'ovei gei pareterto

Note that the words kilto etc. are verbs. kilto means "is a group of a thousand", as in mi viska lo kilto be loi manti, I see a thousand ants.