User blog comment:Ferblover/Ferb's Fanart/@comment-2024558-20100613234752

@FL Um... In Phineas and Ferb's Quantum Boogaloo (or how ever you spell it, I'm crabby today), Linda said that the boys were 30 in that year. They went 20 years into the future, and 30 - 20 = 10.