If the sum has two digits then write down the last digit of the sum in the hundreds-column and write the carry digit to its left : on the thousands-column.
12.
If the multiplicand has a hundreds-digit, find the product of the multiplier and the hundreds-digit of the multiplicand, and to this product add the carry digit if there is one.
13.
Write the " carry digit " above the top digit of the next column : in this case the next column is the tens-column, so write a 1 above the tens-digit of the first number.
14.
This is in contrast to lattice multiplication, a distinctive feature of which is that the each cell of the rectangle has its own correct place for the carry digit; this also implies that the cells can be filled in any order desired.
15.
If the sum was 18 then adding the carry digit to it will yield 19 . If the sum of the tens-digits ( plus carry digit, if there is one ) is less than ten then write it in the tens-column under the line.
16.
If the sum was 18 then adding the carry digit to it will yield 19 . If the sum of the tens-digits ( plus carry digit, if there is one ) is less than ten then write it in the tens-column under the line.
17.
Write the " carry digit " as a superscript of the yet-unwritten digit in the next column and under the line : in this case the next column is the tens-column, so write the carry digit as the superscript of the yet-unwritten tens-digit of the product ( under the line ).
18.
Write the " carry digit " as a superscript of the yet-unwritten digit in the next column and under the line : in this case the next column is the tens-column, so write the carry digit as the superscript of the yet-unwritten tens-digit of the product ( under the line ).
19.
The tens-digit of the first number is 5, and the tens-digit of the second number is 7, and five plus seven is twelve : 12, which has two digits, so write its last digit, 2, in the tens-column under the line, and write the carry digit on the hundreds-column above the first number:
