he meant that according to the instruction inside the Kata 9 should be VIV instead of IX.

Obviously google says otherwise, but that's because google provides more info on this

from the instructions should be VIV

Where are you reading that? A simple search in Google would save you a lot of time.

i do not familiar with roman letters so my strategy was very poor but this is due to missing information about those letters
for example 9 is IX which from the instructions should be VIV and 900 is CM which should be DCCCC

ive spent about 1/2 hour about this but ill pass this one :(