Calculation Castle: Greco's Ghostly Challenge "Subtraction"

Calculation Castle: Greco's Ghostly Challenge "Subtraction" is a game that lets players enjoy studying while challenging their skills in math. It contains a collection of subtraction problems and math drills learned at the elementary level. There are up to 10 steps of learning, starting with elementary 1st grade level 1-digit math problems to developing skills such as borrowing numbers with 2-digit math problems and more. Advancing through the levels, players can naturally learn to solve 4-digit subtraction problems with ease. The game is composed of a series of stages and there are ghosts and locked doors within each stage. Greco and his ghosts will present the player with problems that they will need to solve in order.

"The name's Greco. I'm sendin' you an invite to face the challenges that await in my castle! So, let's play a game!! I live at the very top of my castle! Do you got what it takes to reach me? It won't be easy. In order to get to me, you gotta pass through several rooms. In these rooms, you'll have to solve subtraction problems to pass. That's why my castle is called the Calculation Castle! Moreover, my castle is full of ghosts with many tricks standing in your way, so good luck and do your best! If you manage to beat my ghostly henchmen and get through the rooms, you'll receive lots of hidden rewards…but can you do it? I guess I'll wait and see! Heh heh heh…"