OUR 13-YEAR-OLD daughter is just starting eighth grade at Penn Wood Middle School in the William Penn School District near our home in Delaware County. Her favorite subjects are science and math. But her school cannot support 21st-century science and math programs. In past school years, there were no textbooks for students to take home, so she would bring home worksheets that were not very challenging. There were no fancy robotics or technology programs. And the average size of her classes ranged from 28 to 35 students. She and our two other children, along with 5,000 other students in the district, have missed out on important curriculum because Pennsylvania's Legislature is severely underfunding our schools.

As parents, we will do what we can to try to ensure our kids have a bright future. That's why we joined with families, school districts and advocacy groups from across Pennsylvania in 2014 to file a lawsuit against the state for failing to uphold our state constitution, which requires the legislature to provide a "thorough and efficient system of public education."

Soon, our children will move one step closer to having their day in court. On Tuesday, in Philadelphia's City Hall, the Pennsylvania Supreme Court will hear oral argument to determine whether our case will get a full trial. We want a trial, so that we can show just how deeply our schools are plagued by the state's broken school funding methods. We want the court to step in, hold state officials accountable, and protect the fundamental right all Pennsylvania children have to a high-quality education.

We know firsthand the grave disparities that exist between poor and wealthy schools in Pennsylvania. We moved into the William Penn School District a few years ago to buy a home to accommodate our growing family. Before that, we lived in Upper Moreland, an affluent township in Montgomery County with a larger tax base. According to the latest available data, which is for the 2014-15 school year, the Upper Moreland School District has $2,600 more available per year to spend on each student than William Penn, despite the fact that William Penn's student population needs more resources, not less. In our daughter's middle school, 75 percent of students are economically disadvantaged, compared with 30 percent of students in the middle school she would have attended in Upper Moreland.

That $2,600 makes a difference. In Upper Moreland, there were fewer students per class, the schools were modern, and the teachers were better paid and more experienced. Now, our kids are in schools where the teachers and administrators are forced to do more with less, but, even with their passion and determination, they can't overcome the gaps in resources.

Our working-class community pays our share of property taxes. Our property tax rate is 67 percent higher in William Penn than it was in Upper Moreland. But because William Penn has a smaller, poorer tax base, even with higher rates, the district raises less, and our children suffer while wealthier communities are able to raise excess money for robotics programs and rainy-day funds.

They say that a child's ZIP code should not determine his or her right to a quality education. But we know the simple act of crossing a school district border can drastically change a child's life.

The only way all children will be able to get the resources they need to succeed is if the state provides enough money and distributes it equitably. State leaders took a step in the right direction by adopting the funding formula, but that formula applies only to new funding, and the vast majority of aid is still distributed in ways that reinforce inequality and put poorer districts at a disadvantage.

And while this year's state budget provides $200 million more in basic education funding, that money doesn't come close to meeting our needs. Our district will receive less than $1 million in new funding. That's simply not enough to upgrade our aging buildings or offer the classes our children need to compete in the 21st-century economy.

It is clear, after the last year and a half of budget impasses and disappointing, marginal improvements in education funding, that this lawsuit is the best chance our students have to break through the political gridlock. It's time for the Pennsylvania Supreme Court to follow more than 30 other states who have sent school funding lawsuits to trial. It is time for our judicial system to hold leaders in Harrisburg accountable to meet their constitutional responsibilities. Our children have waited long enough.

Jamella and Bryant Miller live in Delaware County.