I am trying to write a simple app on the APP DESIGNER. Its a basic kids game where they choose the level of difficulty, where random numbers will be given, if low then random number from 1- 5, medium...

I am trying to write a simple app on the APP DESIGNER. Its a basic kids game where they choose the level of difficulty, where random numbers will be given, if low then random number from 1- 5, medium 1-50 and hard 1-100. After the person chooses the level of difficulty they can choose the operation. Once they have chosen the game will generate 5 different problem, every time they hit next will make a new one until the 5 are complete. At the end it will use a counter to display the percentage that the person got correct :)
I have attached the work i have done, thank you