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.
zero | no |
one | pa |
two | re |
three | ci |
four | vo |
five | mu |
six | xa |
seven | ze |
eight | bi |
nine | so |
ten | pano |
eleven | papa |
twelve | pare |
twenty | reno |
thirty | cino |
forty | vono |
hundred | panono |
thousand | panonono / paki'o |
million | paki'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.
one half | pimu / fi'ure | xadba |
one third | pira'eci / fi'uci | |
two thirds | pira'exa / refi'uci | |
one fourth | piremu / fi'uvo | |
three fourths | pizemu / cifi'uvo | |
one seventh | pira'epavorebimuze / fi'uze | |
3+1/7 / 22/7 | vei cisu'ifi'uze / cipira'epavorebimuze / rerefi'uze | |
10-12 | piki'oki'oki'oki'opa | vei gei ni'upare | picti |
10-9 | piki'oki'oki'opa | vei gei ni'uso | nanvi |
10-6 | piki'oki'opa | vei gei ni'uxa | mikri |
10-3 | piki'opa | vei gei ni'uci | milti |
.01 | pinopa | centi | |
.1 | pipa | decti | |
100 | pa | vei gei no | pamei |
10 | pano | dekto | |
100 | panono | xecto | |
103 | paki'o | vei gei ci | kilto |
106 | paki'oki'o | vei gei xa | megdo |
109 | paki'oki'oki'o | vei gei so | gigdo |
1012 | paki'oki'oki'oki'o | vei gei pare | terto |
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.