Make 0-9 app analytics for December 9

When I was in elementary school, looking at the car license plate "I wonder if I can somehow calculate 0-9 using these numbers and symbols." And I used to do that. Now that I'm an adult, I thought it would be nice if there was a brain training app that I could play like that. You can play in 4 difficulty levels. ・Easy "Let's play with 3-digit numbers!" ・Normal "Let's play with 4-digit numbers!" ・Hard "Let's play with 5-digit numbers!" ・Very Hard A super difficult mode with a 5-digit number! Let's calculate everything from 0 to 29. It's surprisingly difficult, so please give it a try.