Early Primitive Elvish
tuku
root. *search, find
tuksa
root. *hundred
saka
root. *search
tuksk-
cardinal. *hundred
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
An unglossed root in the Qenya Lexicon of the 1910s with variant ᴱ√TUKU⁽²⁾ and derivatives like ᴱQ. tuksa “gross, 144” and ᴱQ. tuksa pínea or tuksa lempea “100”, the variation in meaning likely due to the use of the word in duodecimal vs. decimal counting (QL/95). In the Early Qenya Grammar of the 1920s, ᴱQ. tuksa was used only with the sense “100” (PE14/49, 83). This is the last clear reference to an Elvish word for “100”, so I recommend keeping a Neo-Root ᴺ√TUKSA for this purposes, though Q. haranyë “century” (LotR/1108) hints that Tolkien may have used some of other construction for “100” in his later writings.