We leverage an obscure set of rules in Texas's school funding formula granting some districts additional revenue as a function of size and sparsity. We use variation from kinks and discontinuities in this formula to ask how districts spend additional discretionary funds, and whether these improve student outcomes. A $1,000 annual increase in foundation funding, or 10% increase in expenditures, yields a 0.1 s.d. increase in reading scores and a near 0.08 increase in math. In addition, dropout rates decline, graduation rates marginally increase, as does college enrollment and to a smaller degree graduation. These gains accrue in later grades and largely among poorer districts. An analysis of budget allocations reveals that additional funding only marginally affects budget shares.