It will reach at least some classrooms in more than 16,500 public schools, or about 1 in 6 public schools nationwide, according to the charity.

Among them is Marina Del Rey Middle School in Los Angeles. Heather Vibbert, a special-education teacher there, had six requests fulfilled as a result of this week’s donation.

As a result, her students, many of them from low-income households, will benefit from new science DVDs, a Blu-ray player, art supplies and individual white boards, among other things. The highlight, though, will be a Google Expeditions Kit, which will enable them to take virtual field trips.

“I can guide them through the ocean bottom or Mars or any kind of crazy place we can dream of, which I’m very excited about,” Ms. Vibbert said. “That was kind of my big aspirational project that I never thought would get funded, but it never hurts to ask.”

No one understands that better than Mr. Best, who in January reached out to the Ripple chief executive, Brad Garlinghouse, a longtime supporter of the charity, with an audacious proposal: What if the business fulfilled every request on the website?

Mr. Best hesitated to send the email at first, fearing that he might offend Mr. Garlinghouse, but pushed ahead, acknowledging upfront that he was making a “wildly ambitious pitch.”

“I just hope you don’t mind my swinging for the fences,” he wrote.

It paid off. Soon, Ripple invited him to San Francisco to make the case in person and, within about a month of receiving the email, the company had agreed to make the donation.