Ali Baba
Previous research has suggested that mental abacus relies on visual working memory, but it wasn’t clear how children kept track of all the columns: a typical abacus might have more than 15 columns, yet most people have trouble simultaneously visualising more than three or four distinct items in their minds.
In one experiment, Frank and Barner studied children who had spent a year learning to work a physical abacus and had recently begun practicing mental abacus. The pair asked the students to perform challenging additions. Most of them had difficulty performing calculations with numbers that had more than three or four digits. Frank suggests that the children only represent three or four columns of an abacus in their minds at any given time.
In a second experiment, the pair asked 15 expert mental abacus students to do complex calculations while listening to the story Ali Baba and the Forty Thieves. At the same time, these children had to repeat each word of the tale as they heard it – a language task – or drum their fingers on the table – a motor task – or do both.