What’s 2 9/10 - 2 1/3 ? ? can’t seem to get

This is quite easy if you follow steps:
lets start by subtracting the whole numbers
2-2=0 

9/10-1/3
first make the denominator same,
lets keep it 30, now change numerators
27/30-10/30
=17/30

4should be the last one n=4