On page 9 they say total enrollment including charter school in 131,541. It also says non charter enrollment is 117,249.
On page 35 you can see the breakdown of expenses excluding charters so it’s probably more accurate to compare expenses to 117K students.
The 3 major ones being.
Certified Salaries 516 million
Classified Salaries 218 million
Employee Benefits 311 million <- This is the invisible killer. Employees don't see it on their paycheck as an amount but it's increased from 276 million in 2007-2008 even with fewer staff. Everything else has decreased.
Total expenditures on page 38 are 1.11 billion. So it seems pretty accurate to say 1,111,000,000/117,000 ~ 10K spending per kid.
On page 36 you can see the number of positions by type. Basically 5000 classroom teachers and then about another 2500 employees related to special education. That is only 7500 of a total staff of 12,848. So there's quite of bit of not in the classroom staff in the budget.