The police are crime-solvers, but an Ohio officer faced the task of solving a different kind of problem: maths homework.

Lieutenant B.J. Gruber at the Marion, Ohio Police Department recently received a Facebook message from 10-year-old Lena Draper asking for help with mathematics equations.

"I'm having trouble with my homework. Could you help me?" Lena sent in a message to the department.

"What's up?" Lt Gruber replied.

In a series of exchanges later posted by on Facebook by Lena's mother, Molly, Lt Gruber advises Lena on how to solve two equations - unfortunately getting the second one wrong.

"The fact that I gave her a wrong answer was kind of tough," he admitted to Inside Edition.

"Maths's the other side of the brain - I'm more of a creative type," added the father of four, who has worked at the department for more than 20 years.

However, Lt Gruber took it in his stride, telling the BBC: "We really see this not different that a child walking up to an officer on the street and asking for help. This is just a 21st Century version of that interaction."

His department seemed to think so too, tweeting on Monday (Feb 20): "We are nailing our goals of increasing trust, transparency & being approachable. Still a work in product on the maths skills."

The post, which was uploaded on Saturday (Feb 18), has been shared more than 2,700 times, with Ms Draper thanking the department "for truly building relationships with the community".

"We do however encourage kids to communicate with parents, teachers, siblings and fellow students before asking us," Lt Gruber added.