“deci” is very popular. Just not in the “correct” form “decimeter”.
In Spanish it’s normal to say “8 décimas”, which means 8 tenths. It is context dependent though. For example if speaking in a context where millimeters are used, it will be 8 tenths of a milimiter. That is, 0,8mm.
But yeah, it is very uncommon to use deci and deca. Because they’re just not very useful. We are used to 2 digit numbers, or numbers with 2 decimal places. So 87m is not harder to use than 8,7dam.
It’s probably also the reason there is no prefix between kilo and mega, or milli and micro. (They are x1000 increments instead of x10).
For the same reason, when in a context of millimeters, it’s preferred to say “87mm” instead of “8,7cm”.
“deci” is very popular. Just not in the “correct” form “decimeter”.
In Spanish it’s normal to say “8 décimas”, which means 8 tenths. It is context dependent though. For example if speaking in a context where millimeters are used, it will be 8 tenths of a milimiter. That is, 0,8mm.
But yeah, it is very uncommon to use deci and deca. Because they’re just not very useful. We are used to 2 digit numbers, or numbers with 2 decimal places. So 87m is not harder to use than 8,7dam.
It’s probably also the reason there is no prefix between kilo and mega, or milli and micro. (They are x1000 increments instead of x10).
For the same reason, when in a context of millimeters, it’s preferred to say “87mm” instead of “8,7cm”.