【Game description】Mental arithmetic with flashing numbers

1,You can set number of digits, number of times, and speed of flash in the settings.

2,Flash starts when you click "Start" on the upper left.

3,Add up all the displayed numbers, answer the total with the number buttons, and press "Send" to see the result (correct or wrong).

4,If the answer is correct, you can move to the next question by clicking "Next" on the upper left.

5,If the answer is wrong, you can redisplay the flash with "RETRY" on the upper left.

6,After the correct answer, you can return to No.1.