for simplicity consider a pair of three-digits numbers. write the last digit of the second number under the last digit of the first number, forming the ones-column. immediately to the left of the ones-column will be the tens-column: the top of this column will have the second digit of the first number, and below it will be the second digit of the second number. immediately to the left of the tens-column will be the hundreds-column: the top of this column will have the first digit of the first number and below it will be the first digit of the second number. after having written down both factors, draw a line under the second factor.