By Andrea Lucia

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ROCKWALL (CBSDFW.COM) – A 15-year-old with autism found a mistake in a geometry textbook, prompting the publisher to make a correction.

“He loves math. We used to home school and he would do his brother’s math workbooks just for fun,” said his mother Sheri Tharp.

“It’s kind of easy, as subjects go,” said Logan.

The teen found it strange a few weeks ago, when he couldn’t figure out a problem.

“The answer seemed… it seemed wrong,” he said.

He took it to his teacher, who realized the mistake wasn’t in his work, but in the textbook. The writers had missed a step.

Logan’s mother says, he’s had plenty of challenges in life.

“He didn’t actually start speaking until he was five,” she said.

Logan’s way of thinking, though, also helps him catch what others miss.

His parents had no idea about the textbook error until a teacher wrote them Sunday.

“We received a letter and an e-mail from the president of the textbook company that said we were the first to catch the mistake and they are printing new textbooks and sending them to us at no cost,” read the e-mail.

“I’m just really proud,” said his mother, in tears.

Logan doesn’t think it’s that big of a deal, but doesn’t mind the attention.

“I just thought that it was just an innocent mistake. I didn’t know that we’d be here on TV “ he said.

The school principal will award Logan a certificate Tuesday morning, acknowledging his accomplishment.

The publisher also sent a thank you letter, which Logan’s teacher has framed.

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