You might not be able to teach an old dog new tricks - but what about basic maths to a 12-year-old Labrador?
Beau the canine calculator is quickly becoming something of a celebrity in Montana where he can be seen showing off his counting skills in shops, restaurants and cabins.
The prodigal pooch can add, subtract and do square roots - with his owners claiming an incredible 85 per cent accuracy rate - just as long as he's fed a treat for his endeavours.
Maths genius: Dave Madsen with Beau the canine calculator, who can add, subtract and work out the square roots of numbers
'I've had dogs all my life, but this dog is different. He's super smart,' said proud owner David Madsen, who has also taught his mastermind mutt how to count in Spanish.
Beau began learning maths after David laid out a handful of dog biscuits and rewarded him when his number of barks corresponded to the number of treats.
After catching on, his training was upped, until he was counting to ten. Now he can answer questions about golf and football scores, and read simple sums from pieces of paper.
And to tell he has finished answering a question, Beau always shoots his ears into an upright and locked position after the final bark.
Performer: When Beau is not showing off his maths skills, he can be found swimming in the waters near David's Flathead Lake home
But his skill comes at a price. David added: 'If I don't have treats, he gets tired of it after two or three questions. He doesn't work for free.'
Cynics would say David is secretly signalling to his mongrel about how many times to bark, or when to stop. But he still manages to perform his trick after his owner has left the room.
David's son Matt said: 'My dad had a buddy in Atlanta who was determined to prove we were signaling him somehow.
'He took Beau out on the back deck by himself and drilled him one-on-one for 30 minutes, and when they came back in, all the guy said was, ‘You know what? That dog's a genius.'
David, a retired AT&T executive who is married to Patti, adopted Beau as a puppy from his daughter Melissa when she was a student at Georgia Southern University, in Statesboro, Georgia.
Melissa found the three-month-old hound on her doorstep and took him in.
Impressive: Beau started learning maths after dog biscuits were laid out and he was rewarded when his number of barks corresponded to the number of treats
After advertising around the campus that she had found a lost dog, the owner called saying he wanted him back.
But Melissa had fallen in love with Beau, and so her boyfriend at the time Brad Canady, who is now her husband, bought him back for several hundred dollars.
Because she lived in a flat share where pets were not allowed, her parents took him in.
Melissa now has joint custody of Beau with her parents - with the dog spending the summer months with David and Patti when they are at their Flathead Lake home, and in Georgia with her for the rest of the year.
Beau had a brush with stardom in the early noughties when he auditioned for the Stupid Pet Tricks segment on CBS's The Late Show With David Letterman.
But, although the producers loved him, he did not make the final cut for the New York show, and so had to be content with appearing on a local television station - from where he soon became the talk of the town.
Chris Ricciardi, chief of the Finley Point-Yellow Bay, Montana Fire Department, vouched for Beau's skills.
He said: 'Dave will say, 'What's two and three?' Then the dog will go, 'Bark, bark ... bark, bark, bark,' This dog is amazing.'
Originally posted by dailymail.co.uk