Catherine Brown, Scott Sargrad and Meg Benner for the Center for American Progress: In 2014, parents of students at Horace Mann Elementary School in Northwest Washington spent more than $470,000 of their own money to support the school’s programs.

With just under 290 students enrolled for the 2013-14 school year, this means that, in addition to public funding, Horace Mann spent about an extra $1,600 for each student. Those dollars, equivalent to 9 percent of the District of Columbia’s average per-pupil spending, paid for new art and music teachers and classroom aides to allow for small group instruction. During the same school year, the parent-teacher association raised an additional $100,000 in parent donations and collected more than $200,000 in membership dues, which it used for similar initiatives in subsequent years. Not surprisingly, Horace Mann is one of the most affluent schools in the city, with only 6 percent of students coming from low-income families. …