This is the famous flash anzan which can be used to practice mental math. Numbers flashing on the screen have to be added or subtracted. If you find any problems or have suggestions feel free to contact me.
# Digits: Number of digits. 1 meaning any number between 1 and 9, 2 meaning any number between 10 and 99, and so forth.
Length: This will be the amount of numbers being flashed consecutively.
Time: This is the time in seconds each number is flashed.
Mode: You can choose between addition only or a mixture of addition and subtraction.
Leaderboard: The leaderboard is reshuffled weekly. Reset is every Sunday at 23:59:59 UTC. There is a seperate ranking for each # Digits. For being first by the end of the week you will earn a star (★)