CHATTANOOGA (WRCB) -- His second graders have reached the point that Daris Waters calls "show what you know."

"What's my first step," he asks.

"You want to borrow a ten so the two becomes a 12," a young man answers softly but confidently.

Subtraction is the day's lesson. But could a school voucher program change the equation, and the student body at Grace Baptist Academy in eastern Hamilton County?

"My heart is to help such if they're struggling," headmaster Dr. Bill Summers says. "To find some place we can get them prepared for the future."

"If a parent can say, 'I think my child would be better off in this situation,' I think that's a good thing," Governor Bill Haslam says.

Haslam's voucher program, now before Tennessee lawmakers, would allow parents to move the state and local tax dollars allotted for their children's education, to pay tuition and fees at private or church-supported schools. 

But children would qualify only if their schools are among the lowest five percent in achievement, based on student performance on standardized tests. Their parents would have to meet income guidelines; qualifying for free or reduced-price school lunches.

"We thought it was important to wade into this," Gov. Haslam says. "To see the impact that it had, without being too much of a shock to the system."

As outlined in House Bill 190 and Senate Bill 196, the Tennessee Choice & Opportunity Scholarship Act would make vouchers available only to 5,000 students in the 2013-14 school year.

The number would rise to 7,500 in 2014-15, 10,000 the following school year, and 20,000 in 2016-17.  

Majority Leader Gerald McCormick (R-Chattanooga) is sponsoring the House bill.

"I've heard that this program will drain resources from schools that need them the most," Gov. Haslam concedes. "But we've actually put $37 million more in the budget for such schools."

Six of Tennessee's 83 'priority' or 'at-risk' schools are in Hamilton County; Brainerd High , Chattanooga Girls Leadership Academy, Dalewood Middle School, Orchard Knob Elementary and Middle Schools, and Woodmore Elementary

"There are so many things we have still questions about," Dr. Summers says.

Most notably, the fourth 'R.'

"If you're a Catholic school, a religious school of any kind, you won't have to change your school's philosophy," Gov. Haslam says.

Some supporters of public schools argue that public (tax) dollar-support of religious-based education violates First Amendment prohibitions providing for 'an establishment of religion,' most commonly referred to as separation of church-and-state.

"Our curriculum is Christian-based; we certainly wouldn't change that," Dr. Summers says. "We'd have to ask whether accepting vouchers also would require us to accept other changes in our admissions or our standards."

The Choice Act would require voucher schools to accept Tennessee's Comprehensive Assessment Program (TCAP), the Department of Education's statewide program to measure student skills and progress. Students in grades 3-8 take Achievement Tests. High school students take end-of-course exams.

"There will be something to show that you're adding value, academically for that child," Gov. Haslam explains.

Parents may find that 'added value' also requires that they themselves accept more responsibility and accountability, Dr. Summers says.

"Education doesn't end in the classroom. We expect parents to be involved," Dr. Summers says. "Ours volunteer in the classroom, run sports booster clubs, help keep the school grounds clean. They're everywhere."

Grace Baptist Academy educates more than 600 students in grades K-12. 

"We could hold as many as 900, but it's not about numbers," Dr. Summers says. "Our tuition ($5,000-$7,000 yearly) is among the lowest for private education around here, and the voucher likely would cover it."

Costs, or revenues would not drive whether his school would accept, or reject a voucher program, Dr. Summers asserts.

"It's about the students," he says. "Those we already have, and those whose parents would want them to come here."