next, the hundreds-column. the hundreds-digit of the multiplicand is 7, while the multiplier is 3. the product of 3 and 7 is 21, and there is no previous carry-digit (carried over from the tens-column). the product 21 has two digits: write its last digit in the hundreds-column under the line, then carry its first digit over to the thousands-column. since the multiplicand has no thousands-digit, then write this carry-digit in the thousands-column under the line (not superscripted):