It's a British sort of joke phrase such that when asked the reply or answer is:
Bean, bean, bean and a half, half a bean and a bean.
My father used to ask me this when I was young and it was told to me as,
"Two beans, a bean and a half, half a bean and a bean."
After looking at various sources trying to
figure out why anyone started saying this at all, I came across many versions. They all seem to contain most of
the following parts in some arrangement: two beans, a bean, bean and a
half and half a bean. I decided on this version because if listen you can hear the rhythm like a poem.
"Bean, bean, bean and a half, half a bean and a bean."
Oddly about 1 in 5 of the answers didn't actually add up to 5 beans.