How would you say 10.00 on french?

10.00 implies an accuracy of ± 0.005

The spoken French for this is dix virgule zero zero.

dix is the French for 10 (which need only be accurate to ± 5 or ± 0.5; it depends on the context.)

Note that the English 10.00 with a full stop ("period" in American English) used as the decimal point would be written in French as 10,00 (with a comma - hence "virgule".) The full stop ("point" in French) is used to separate thousands, in the way that a space or comma is used in English.