We went to Moscow for a visit to my aunt.There, every day it was necessary to ride a bus and not to pay for the younger sister (8 years old), asked her to say that she is still 6 years old (for those who do not know children up to 7 years in public transport ride for free).So, they were trained, and on the question: "Pola, how old are you?" the child confidently replied: "Six."
Her mother came to visit her aunt and asked, "Pola, how old are you?" and the child replied, "Well, I am eight, but six for the bus."

Billy-Villy