Locate the line on the right side of the check that begins with a dollar ("$") sign, next to the "Pay to the Order of" line.
Write "15,000," and then write the "10" smaller, higher, and to the right, with a slash and a "100" to indicate that it is ten cents out of a hundred: "10/100." This number should begin as close to the dollar sign as possible, so that no one can add another number in front of the amount.
Locate the line in the middle of the check, beneath the "Pay to the Order of" line, and with "Dollars" printed on the far right.
Write "Fifteen thousand and 10/100" on the line, starting on the far left. If there is a blank space between the "10/100" and the printed word "Dollars," draw a wavy line to fill the space so that no one can tamper with the amount.