"Math is hard. Let's go shopping!"

Thus spoke Barbie nearly 20 years ago, and the sentiment still holds water today. Why do your own math when you can just wait for someone else to do all of the hard work?

So I'd like to thank uber-blogger John Battelle for doing some math today. Using nothing more than middle-school subtraction and division, John shows that Google's (Nasdaq: GOOG) Android is beating Apple (Nasdaq: AAPL) on the open market by a wide margin.

According to Battelle's math, Apple has moved about 130,000 iPhones a day since the debut of iPhone 4. Back out the mad rush to get one on release day and the run rate drops to maybe 65,000 a day. Not bad. But Google reports that 160,000 Android phones get activated each and every day, which blows even the more generous iPhone stat to smithereens.

"As far as I can tell, Android-based phones will far outnumber any other smart phone by year's end," Battelle says. "Apple, meet your new Windows. It's name is Android."

Indeed, Google seems like a closer head-to-head rival for Apple these days than crusty old Microsoft (Nasdaq: MSFT). Mac vs. PC debates are gathering dust now while iPhone versus Android is the new hotness. The funny part of that is, Google doesn't really want to beat the iPhone in sales. After all, the company gets about zero dollars in license fees from Android-powered smartphones. Now that the Nexus One is obsolete and only available to Android developers, there's no value to Google in Android sales. What Google wants is better smartphones in general, so that we all click on more online ads while on the go.

Apple, on the other hand, profits handsomely from every iPhone sold by Apple stores, AT&T (NYSE: T), Vodafone (NYSE: VOD), and other retail outlets the world over. The two companies have entirely different stakes in this two-horse race. Sorry, Nokia (NYSE: NOK) and Research In Motion (Nasdaq: RIMM): You're both losing global market share to these smoking-hot upstarts.

So thanks for doing the math, John. Now let's see what Apple plans to do about these embarrassing figures. (Embarrassing figure? Ask Barbie, perhaps.)

Fool contributor Anders Bylund holds no position in any of the companies discussed here. Microsoft and Nokia are Motley Fool Inside Value recommendations. Google is a Motley Fool Rule Breakers choice. Apple is a Motley Fool Stock Advisor recommendation. Motley Fool Options has recommended a diagonal call position on Microsoft. The Fool owns shares of Google. Try any of our Foolish newsletters today, free for 30 days. You can check out Anders' holdings and a concise bio if you like, and The Motley Fool is investors writing for investors.