Long multiplication is a method used to multiply multi-digit numbers by hand.

1. Stack Numbers: Write the numbers one below the other, aligned to the right.
2. Multiply by Ones Digit: Multiply the top number (the multiplicand) by the rightmost digit of the bottom number (the multiplier). Write this result (the first partial product) below the line.
3. Multiply by Tens Digit: Multiply the top number by the next digit to the left in the bottom number. Write this second partial product below the first one, but shifted one position to the left (add a zero at the end).
4. Continue: Repeat for all digits in the bottom number, shifting each new partial product one more position to the left.
5. Add Partial Products: Add all the partial products together using column addition to get the final result.

Disclaimer: This calculator is provided for educational purposes only. While we strive for accuracy, we do not guarantee the results will be error-free. Always double-check critical calculations.