Chromebooks Gaining on iPads in School Sector - The New York Times

That's compared to, for the U.S. education market in 2014, ~4.9M Windows devices and ~4.2M Apple (iOS/Mac OS) devices

"But the Chromebook category is fast gaining traction in the United States.

Last year, about 3.9 million Chromebooks were shipped in the education sector, an increase in unit sales of more than 310 percent compared with the previous year, IDC said. By contrast, iPad unit sales for education fell last year to 2.7 million devices, compared to 2.9 million in 2013, according to IDC data.

“Even if Microsoft is No. 1 in volume and Apple is No. 1 in revenue, from the growth perspective, nobody can beat Chromebook,” said Rajani Singh, a senior research analyst at IDC who tracks the personal computer market and is the author of the report."

Chromebooks Gaining on iPads in School Sector - The New York Times