Click on a selected number and then the sign of operation, the second number and the result. Sqr - is a square root of the number, ^ 2 - is a square number.
Double-clicking - resignation of the selected numbers.
The numbers are incomplete only in the results of operations.
The clearing of the board is a bonus 1000 points!
The level can be counted before (when the limit = 0) by clicking on OK.
Points are for the remaining time at the moment. Error = -50 points.