With this version there is no worry of a flap that pivots out and away from the slate as in the first Al Baker version.
Three persons each think of a number the first a number from 1 to 100 the second a number from 100 to 200 and the third a number from 200-300.
As these numbers are spoken aloud they are written upon the slate. Any one may total the numbers and a prediction made prior to all of this is opened and it matches exactly the sum total!
The slate measures 7 inches x 13 1/2 inches with a thickness of 3/4 inches and the frame is made of wood. This shows moderate use.
If you are not familiar with the principle you will be quite pleased with the ease of performance. Includes instructions.