Use this tool for math practice or teaching math. Teach 2, 3, and 4 digit addition with carrying. The gray blocks are used for carrying. Add the columns right to left, carrying 1 into the next column if the sum is greater than 9. When complete, put the cursor on the check mark - blue digits are correct, red ones are incorrect. Use the TAB, SHIFT-TAB, arrow keys, or mouse to move from digit to digit.

Use the buttons at the bottom to generate random math addition problems with up to 2, 3, or 4 digits. This tool was designed for teachers and parents for demonstration when teaching math addition, but can also be used by students to practice addition.