randRange(1, 9) randRange(1, 9) randRange(2, 9) randRange(1, C - 1)
A * 100 + B * 10 + C - D

\Large{A * 100 + B * 10 + C - D = ?}

\Large{= \green{A}\pink{B}\blue{C} - \blue{D}}

\Large{= \green{A * 100} + \pink{B * 10} + \blue{C} - \blue{D}}

\Large{= \green{A * 100} + \pink{B * 10} + \blue{C - D}}

\Large{= \green{A}\pink{B}\blue{C - D}}

randRange(1, 9) randRange(2, 9) randRange(1, 9) randRange(1, B - 1)
A * 100 + B * 10 + C - D * 10

\Large{A * 100 + B * 10 + C - D * 10 = ?}

\Large{= \green{A}\pink{B}\blue{C} - \pink{D * 10}}

\Large{= \green{A * 100} + \pink{B * 10} + \blue{C} - \pink{D * 10}}

\Large{= \green{A * 100} + \pink{B * 10} - \pink{D * 10} + \blue{C}}

\Large{= \green{A * 100} + \pink{B * 10 - D * 10} + \blue{C}}

\Large{= \green{A}\pink{B - D}\blue{C}}

randRange(2, 9) randRange(1, 9) randRange(1, 9) randRange(1, A - 1)
A * 100 + B * 10 + C - D * 100

\Large{A * 100 + B * 10 + C - D * 100 = ?}

\Large{= \green{A}\pink{B}\blue{C} - \green{D * 100}}

\Large{= \green{A * 100} + \pink{B * 10} + \blue{C} - \green{D * 100}}

\Large{= \green{A * 100} - \green{D * 100} + \pink{B * 10} + \blue{C}}

\Large{= \green{A * 100 - D * 100} + \pink{B * 10} + \blue{C}}

\Large{= \green{A - D}\pink{B}\blue{C}}