Given the typical speed of rotation for a slice of toast as it falls from the table and the typical height of a table , a slice of toast that began butter-side-up on the table will land butter-side-down on the floor in 81 % of cases .
Using the average speed of rotation for a slice of toast as it falls from the table and the usual height of a table , a slice of toast that began butter-side-up on the table will land butter-side-down on the floor 81 % of the time .