REVERE-The failure rate among local high school students is down from 1998 numbers, but Superintendent Paul Dakin worries spending cutbacks could jeopardize future improvements.Dakin’s 10-year student performance review shows students steadily improving mathematics scores, with high school math scores showing the biggest improvement, in part because of spending focused on math courses.”These high school students have had the benefits of the extra time and finances throughout the years,” he said.Dakin anticipates science scores will improve with a renewed curriculum focus in the middle schools.He is worried that reading scores will mirror spending cutbacks in 20-day intensified reading improvement programs. Dakin said lack of spending on summer, afternoon and Saturday school programs will impact student test performance.”Students need more contact with teachers,” he said, adding, “Years from now some superintendent will be here saying that it is impossible to maintain progress because we were not giving students the extra time during the 2006-2010 school years.”Dakin warned before school started in August that without state money 15 additional teachers would not be hired. He said class sizes and other concerns would become major problems next year if the city cannot secure $6.8 million to $7 million in additional state money.Dakin and the School Committee have pinned their hopes of improving test scores in part on the extended school day introduced this year.The Whelan School as well as Garfield Middle School introduced an extended day this year beginning at 8 a.m. and finishing at 3:45 p.m. The extra time is devoted to tutoring and homework as well as art and other programs bumped from the regular school day.Dakin would like to get state approval and funding to expand extended day to Beachmont, Paul Revere, Garfield Elementary, Anthony Middle School and the McKinley School.