It seems that what you actually expect from the numbers is:

8.9 > 8.10 and this is true with the decimal numbers, but when talking about the version of a software this is not true because each number after the dot have individual meaning resulting that the version 8.9 < 8.10 

So the operation

(3 - 10) % 27

result in 20, because when you insert a negative number in the first operand the modulus return a positive result changing this

-7 % 27

to this

-7 + 27

resulting in 20