A new report finds tens of thousands of children in the city are missing a lot of school.

The analysis by the Center for New York City Affairs at the New School says during the 2012-2013 school year, more than 87,000 K-5 students missed more than a month of class.

Kim Nauer, a co-author of the report said recent efforts by Mayor de Blasio to address poverty related education issues should also focus on boosting attendance.

"The mayor and the Department of Education need to recognize that this figure is as important as test scores in understanding how well kids are doing in school," she said.

The report also found 130 schools where more than a third of students were chronically absent for five years in a row.