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-digi...