Five pounds of kilos

Mrs Murphy told her little boy to go to the shop and buy five pounds of potatoes.

"But buy the small ones" she told him in a stern voice. "The big ones are too heavy"

He arrived at the shop and asked for five pounds of potatoes. The greengrocer shook his head gravely.

"My boy, 'tis kilos these days" said the greengrocer.

"OK" said the boy. "I'll have five pounds of kilos - but only the small ones."