London (CNN)Britain's Queen Elizabeth took part in supermarket retailer Sainsbury's 150th birthday celebrations on Wednesday, and even took the time to learn about self-service checkouts.
Staff demonstrated the checkout, now a ubiquitous sight in shops in many countries, to the British monarch, although she didn't have a go at using it herself, CNN affiliate ITV reported.
However the Queen gamely joked around with staff, asking them if it was possible to cheat the machine.
The monarch was on a tour of a replica 1860s-style Sainsbury's supermarket in Covent Garden, London, near the retailer's first shop on Drury Lane.
The Queen asked if people could cheat the self-service checkout machine.
The original store stocked only the basic essentials, specializing in butter and eggs, but Sainsbury's is now a multi-million pound business.
