Instructions:

Click "Start" to do the drill;

Key Pad:

• Click "Hide/Show Carry" to hide or show carry as a red dot;
• Click "Show/Hide Hint" to show of hide hint;
• Click number keys to enter your answer;
• Click "DEL" to erase the most recenly entered digit;
• Click "AC" to clear all digits;
• Click "=" to check your answer.

Key board:

• Type the number keys to enter your answer;
• Press "Delete" to erase the most recently entered digit;
• Press "Backspace" to clear all digits;
• Press the Space bar, "=" or "Enter" to check your answer.