The Harvest Prep empire of charter schools has been awarded $1.5 million from the Cargill Foundation that it says will help it expand to 3,500 students.

At least, that's the stated goal for the Minneapolis-based group of schools that now includes Harvest Prep for K-6 students, Best Academy for K-8 students, and Mastery school for K-3 students.

Maybe some of the grant can be used for remedial math.

The three schools reported a combined enrollment of 1,114 to the state for last school year. But the press release announcing the grant says that founder Eric Mahmoud wants to increase enrollment by one third to about 3,500 students by 2020, which would be a tripling over last year. A spokesman later said the one-third figure was incorrect.

Cargill said that the three-year grant will help to create the Harvest Network of Schools, to manage services for the three schools and support a growth plan focused on planning, teaching, assessment, instructional leadership, fundraising and financial management.

It was not clear whether that growth will be in partnership with Minneapolis Public Schools, which has a 2012 performance-based clause under which Mahmoud could potentially open three additional schools besides Mastery over the next eight years.

Mahmoud has attracted widespread attention for reaching much higher proficiency rates in reading and math scores among black students than nearby district schools. But math and reading scores took a nosedive in 2013 testing at the two schools where students were old enough to be tested. Although reading scores were down across the state with the introduction of a new standardized test, math scores also fell.