Something didn’t add up, but Matthew Stafford already knew that.

The Detroit Lions quarterback went viral last month for acting like a math wizard during a virtual broadcast for the team’s pre-Draft show, but apparently that’s all it was: an act.

Joining Lions offensive lineman T.J. Lang, the 32-year-old Stafford was asked to calculate 9,758 x 618 in his head. Within a few seconds, Stafford answered correctly — 6,030,444.

“I can’t believe you guys fell for the math trick,” Stafford told reporters on a Zoom call Thursday. “T.J. and I have been doing that for years. He texts me the answer beforehand and I just read it off and sell it hard. I guess I deserve a daytime Emmy, but for sure, not a math award.”

Putting the MATH in Matthew pic.twitter.com/Pd1Elctauw

— Detroit Lions (@Lions) April 25, 2020

Stafford and Lang apparently first pulled the prank on an episode of the online series “Talkin’ with T.J.” a few years back.

The video has accrued over 100,000 views on Twitter.