This afternoon, the city's 86,169 8th graders finally got news about their high-school placements for September. According to the Department of Education, just over half got good news from their first-choice school, three-fourths got one of their top three picks, and 86 percent got one of their top five. (Students who received offers from the eight specialized exam high schools and LaGuardia got their news in February.)Despite a process that permitted student to rank up to 12 general-education schools, 7,455 students came home empty-handed, without having matched to a school on their list. These students will participate in a supplementary round, which launches with a school fair on March 31 from 6 pm - 9 pm at the Martin Luther King Jr. Educational Campus in Manhattan.While the first round of the high-school process spans months, the decision-making window in the supplementary round is short: Applications must be returned to 8th grade guidance counselors on or before April 3.