Bill Gates: My kids get cell phone at age 13

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By Eun Kyung Kim

Bill Gates, one of the world's richest men, faces the same problems at home that all parents do — like dealing with cell phone privileges.

“We’ve chosen in our family that it’s 13 where you get a phone. And you’re still a little bit limited,” Gates, the father of three children, including two teenagers, said Wednesday on TODAY. “They’re always coming home, ‘All the other kids have it. I’m the only one without it, it’s so embarrassing.’”

The admission brought some relief to Matt Lauer. "You just bought me two years, you realize that, right?” he said.

Lauer then asked whether he keeps the passwords to his children’s electronic accounts. Gates said he doesn’t — at least for his 16-year-old daughter.

Related: Bill Gates recalls his 'spontaneous' first date with wife

“She’s independent,” he said, acknowledging, “that’s always a very tricky issue for parents now.”

Gates, who was listed as the world’s second-richest billionaire by Forbes magazine, with a net worth of $61 billion, said spending his money on his philanthropy work is as exciting as earning his first several million dollars from the software company he created.

“What you really feel is what you’ve achieved. If a piece of software gets out there and lots of people love it — it lets them get their work done in better ways — that’s exciting,” the Microsoft founder said. “When polio finally gets eradicated sometime in the next six years, that will feel extremely good.”

Watch video: Bill Gates predicts 'electronic mail' in 1992

Gates and his wife, Melinda, have given away $28 billion through their charitable foundation, both domestically to improve education and internationally to improve global health and nutrition.

One of their foundation’s top goals, described in its annual letter released Wednesday, is to completely eradicate polio, which was eliminated in India last year.

“Getting India done was a huge milestone," he said, but admitted, "It’s going to take a lot of money to finish it, about $6 billion more.”

The disease is still a problem in three countries: Nigeria, Pakistan and Afghanistan. Gates said eradicating it there will take more than throwing money at the problem: “It’s not check writing.”

It will take the use of satellite maps and GPS trackers to make sure vaccination teams are getting to the right spots, particularly in rural areas, he said. In addition to the technology, political negotiations will be crucial to make sure world leaders make the issue is a priority and put the necessary organizational structure in place to distribute the medicine. 

Smallpox is the only disease to have been eliminated by human effort.

"We want to make this the second disease ever eradicated," he said.

For more information on the Gates Foundation's annual letter, click here.

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