Schoolchildren in Massachusetts won't return to their classrooms until at least May 4, Gov. Charlie Baker said Wednesday shortly after signing executive orders to extend the temporary closure of all schools and non-emergency child care centers through April.

"This will allow school districts to provide the best possible opportunities for remote learning to all students and we want to be clear on this ... this is not an extended school vacation," Baker said from the State House.

The governor's announcement came as the Department of Public Health announced 679 new cases of COVID-19, bringing the state's total to 1,838 positive cases. DPH also announced four new deaths due to COVID-19, raising the state's fatality count to 15.

Schools in Massachusetts have been closed for more than a week -- even longer in some cases -- and Baker's initial order temporarily closing schools envisioned a return to the classroom no sooner than April 6. The governor said Wednesday that the extended closure "will allow more time for teachers to ensure that all students have access to resources and instruction that is customized to their particular needs ... [and] provides a runway to ensure that they can complete their coursework by the end of the school year in June."

Elementary and Secondary Education Commissioner Jeff Riley said his department plans to send additional guidance to school districts Thursday morning so that districts can "build upon or harmonize with their current remote learning plans" and implement their revised plans by early April.

"We recognize districts will have the ability to kind of customize their plans for their communities, but we're going to offer some structure by which to focus on that. And so we think getting kids into a routine, keeping them engaged in learning, is the way to go," Riley said. "This is an amazing opportunity to think about project-based learning, to think about reading a book, to think about cooking recipes and how that works, to think about starting a garden. We have a real opportunity here to do different things with our children, and we're going to try to supply the resources in addition to what the district is offering."

Baker said his administration understands that the school closure has been difficult on teachers who are trying to come up with creative ways to engage their students remotely and for parents, many of whom are concerned that their child might fall behind without access to the internet at home.

To address that concern, Baker said the state is partnering with WGBH to make educational resources available online. WGBH will also broadcast educational content on TV from noon until 5 p.m. every Monday through Friday.

"We understand that not every district and not every student has the same access to computers, the internet and tablets. The department will also work with school districts to encourage interactive ways of learning, like exploring nature and participating in activities that incorporate social distancing," Baker said.

Neither Baker nor Riley explained Wednesday what the decision to close schools through April will mean for annual MCAS testing. The Massachusetts Teachers Association has been calling for the cancellation of MCAS exams this spring and Baker on Tuesday filed a bill with the Legislature that would grant Riley the authority to modify or waive the annual statewide MCAS assessment, and for the state education board to modify or waive the requirement that MCAS scores be used as part of graduation criteria.

"I think we need to wait first until we see if we get the federal waiver, which we have applied for, around testing. And then we need to wait to see if the state legislation that was sent up by the administration yesterday will grant me the authority to make such decisions," Riley said. "You should expect that once those hurdles are cleared, that I will make decisions in short order about the MCAS."

The MTA applauded the governor's announcement Wednesday and said it believes he is following the advice of the medical experts. MTA President Merrie Najimy said her organization is "withholding judgment" on Riley's promised remote learning guidance until it can review the plan.

"As always, our primary concern remains the well-being of students, educators and our communities," Najimy said. "We will continue to do everything we can to ensure that the state makes a significant and consistent impact in stemming the spread of the coronavirus and working for the common good of everyone in Massachusetts."

The governor and education commissioner both sought the silver lining in Wednesday's announcement. Baker touted the benefits of applied learning and said he hopes the next five-plus weeks will lead to the ability to do some "very different things with respect to educating and encouraging kids."

"I think only time is going to tell on what happens. This could be an amazing opportunity to think differently about how we educate our kids and think about real world applications -- using social distancing, of course," Riley said. "This could be something new that could give us additional information about how kids learn best. We won't know, but it's certainly something we're looking at."

As testing for the virus ramps up significantly following a slow start, the latest report from DPH showed that the highly-contagious coronavirus is continuing to spread across Massachusetts and that the full scope of the pandemic is becoming more apparent.

The number of positive COVID-19 cases in the Bay State shot up by more than 58 percent from Wednesday to 1,838 while the number of people tested increased over the same time period by about 44 percent to 19,794, according to DPH. The governor had said Massachusetts needed to be testing at least 3,500 people each day as of this week, and DPH said Wednesday that "more than 6000 additional individuals" had been tested since Tuesday's update.

The state reported four new deaths from COVID-19 on Wednesday: a Norfolk County man in his 80s who had pre-existing conditions and was hospitalized, a Barnstable County man in his 80s who had pre-existing conditions and was hospitalized, a Worcester County woman in her 70s who had pre-existing conditions and was hospitalized, and a Worcester County man in his 70s who was hospitalized.

While the COVID-19 respiratory illness is said to be most dangerous to older patients, the number of positive results found in patients in their 20s, 30s, 40s and 50s have all surpassed the number of positive results found in patients in their 60s or who are 70 or older.

People 50 to 59 years of age account for 330 of the state's cases, the most of any 10-year age range DPH reports, followed by 326 cases in people aged 20 to 29, and 322 cases among people in their 30s. There are 255 COVID-19 patients over the age of 70 in Massachusetts.

With an eye towards protecting older people who are at a greater risk of dying from a COVID-19 infection, Baker also announced Wednesday that DPH had issued an order requiring grocery stores and pharmacies to provide at least one hour per day of shopping exclusively for people aged 60 or older, to close all self-serve food stations, to make sanitizing wipes available to clean carts and baskets, and to mark check-out lanes with six-foot distances to encourage social distancing.

"As we continue to monitor this outbreak, it's important that these places which are often visited by large amounts of people on a daily basis are observing DPH guidance on sanitation and social distancing," Baker said. "We also need to make sure we make appropriate accommodations for our most vulnerable residents so they can safely do their shopping for food and supplies."

After announcing the plan for a dedicated hour of shopping for people 60 or older, Baker, 63, turned to Riley and said, "Works for me, Jeff. What do you think, how about you?"

Riley is in his late 40s and told the governor he couldn't yet take advantage of the dedicated hour.

"Not there yet," Baker said. "Okay."