A North Carolina man who allegedly cracked the code to mentally calculate any multiplication problem is now offering to reveal his secret - for the bargain price of $33.

Albert Clay said he came up with his system as a high school junior, but never showed anyone aside from a high school math teacher who shrugged off the achievement, the News & Observer reported.

Now 75 years old, the retired pharmacist has copyrighted the formula, "How to Multiply Any Number by Any Number in Your Head," and hopes to demonstrate it in schools, books or even personal mailings to anyone who'll send him $33, including postage, the paper reported.

"There may not be anybody else in the world who knows how to do this but me," Clay, told the News & Observer. "Zip, zip, zap and add 'em together."

True to his word, Clay multiplied a pair of five-digit numbers in just seconds and wrote the answer on a single line of his yellow scratch pad, News & Observer reported. No calculator. No zig-zagging numbers cluttering the page.

"It's not complicated once you crack the code," he said.

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