Last year, as I was sitting in New York City Hall with members of the mayor’s Interagency Task Force on Truancy, Chronic Absenteeism & School Engagement, I learned a sobering fact: about one of every three high school students is absent on any given day.

As a high school teacher in the Bronx in the 1990s, about one-third of my students were absent on any given day. I figured that nearly twenty years later, after an intense focus nationally and in cities like New York City to bolster graduation rates, the attendance problem would have been solved. It never seemed to come up, so maybe it had gone away.

Turns out, if you don’t actually measure, monitor and act on a problem it doesn’t go away.

This week Get Schooled joined Johns Hopkins University School of Education researcher Dr. Robert Balfanz to release “The Importance of Being in School,” a report that highlights the scope of our nation’s attendance problem and the consequences of our inaction.

The report found that up to 7.5 million students (the equivalent of more than all K-12 students in California) miss a month or more of school a year.

Students who miss 20 days or more are deemed “chronically absent.” This doesn’t mean that they are absent for a week or two at a time, it simply means they missed a few days of school each month. Days off that may not have seemed significant at the time – maybe a stomach bug, a family vacation, or just because they were tired. But those days add up.

Many parents might ask why it matters if all those absences were for good reason – and excused.

The data suggests it doesn’t matter if a student’s absence is excused. What matters is that they are not in class learning key concepts. A chronically absent student’s test scores may drop by as much as 20 points, indicating there are gaps in their language, writing and mathematic skills.

It’s simple: If you don’t go to school, you won’t graduate and most importantly you won’t have the fundamental skills you need to succeed in a college or a career.

Yet school attendance has not been a priority. It’s rarely discussed, we don’t measure it in a way that is actionable, and most parents and students are unaware of the consequences of missed school. If we are going to close the achievement gap, and ensure that our children can compete on global scale, it’s time we started making attendance a priority.

Policymakers and education leaders must do more to measure and monitor the problem. The report recommends that chronic absenteeism be included in federal and state data reports. It also calls for early warning and intervention systems, so we can reach and out and support families and students before too much school is missed.

But parents and students play a critical role too. It is important that they recognize that there are consequences to not going to school. We encourage parents and students to try out Get Schooled’s attendance calculator to understand the impact of days missed.

Parents should make school attendance a priority in their homes and how they organize their lives – from the start of their child’s school career. If parents make missing school a big deal, their children will too. They don’t have to do it alone. Parents can encourage their students through Get Schooled wake up calls – students can get an early morning call from one of their favorite celebrities reminding them of the importance of attendance.

Earlier this year, actor and recording artist Ne-Yo attended a Get Schooled event recognizing Aki Kurose Middle School in Seattle for boosting their attendance. Ne-Yo reminded students of an important life lesson: "Showing up is honestly the most important thing you can do, if you don't show up [in life] you can guarantee that nothing will happen."

Ne-Yo’s advice is common sense. It’s time we get the basics right. Let’s work together to ensure our young people are in school “all day every day”.

Marie Groark is the executive director of the Get Schooled Foundation.

All statements and opinions expressed on this blog are those of the individual contributors, and not of the Bill & Melinda Gates Foundation or NBC News.