Honestly, I don't have the exact number of fingers Itadori has eaten off the top of my head. It depends on the detailed plot developments in the manga. You'd have to go through and carefully follow the story to figure it out accurately.
It's hard to give an exact number, but I'd say Itadori has eaten at least 10 Sukuna fingers in the manga. The number keeps fluctuating based on the plot and his encounters with various challenges.
I don't have the exact number off the top of my head. It's best to re-read the relevant parts or look for discussions among manga enthusiasts who might have tallied it up.