The SI units come with prefixes that specify orders of magnitude - all the way from very small fractions to reasonably large - on a human scale - powers of ten.
Now, consider languages with numeral case congruence. If each part of these numbers has congruence for case, you quickly run up some quite huge compounds with numbers. Finnish is a particularly notable example of this:
in five hundred thirty eight thousand three hundred and ...
Now, one could imagine that, for instance, SI units could be abused to avoid this, giving us
viidessä dekatalossa instead ofviidessäkymmenessä talossa
At this point, we'd have a language with singulars, plurals, decals?, centals?, millennals? or whatever to call such numbers.
Of course, it's also easy to imagine a number system with the largest numbers placed to the right within the numeral develop in a way where that number suddenly is prefixed to the noun instead.