Sir Cumference and Lady Di plan a surprise birthday party for King Arthur. They invite everyone from the countryside, but the plans turn into a royal mess. Guests continue to arrive until the castle is full. Lady Di and Sir Cumference need to figure out a quick way to count the number of people for the birthday party. The story introduces place value as the knight and lady count the partygoers in tens, hundreds and thousands.--Ministry of Education website.

Mathematics grade 4 (2007).