This is a flash mental arithmetic app for beginners to advanced users.
You can specify the number of digits from 1 to 5 digits, the number of words from 1 to 20, and the number of seconds in 0.01 second increments in the problem setting.
The problem generation is not simple random numbers, but practical problems that are more similar to tournaments and competitions.
We plan to update it from time to time to further improve the user experience. If you have any opinions or requests, please leave a review.