First, Congrats to both of you, mom and dad, for your parenting skills. About the game, 1 - It is fun to play! Awesome ideia to make it turn based attacks and math problems 2 - The artwork is fun! good jobs.

Suggestions:

What about add difficulty levels? like: Easy: simple addition/subtraction problems Medium: +-/ problems Hard: +-/ problems with a timer (10 to 20 seconds to awnser)