1. Measure the top of your table. You will add 6 to 12 inches on all sides of your tablecloth for overhang, but the length and width should both be divisible by the same number (this number will be the diameter of each scallop); adjust your measurements to make this possible (for example, for a 37"x 74" table, instead of adding an even 8 inches to each side, add 8½ inches to the width on each side and 8 inches to the length on each side to get a 54"x 90" rectangle, which leaves both sides divisible by 9). Mark this rectangle on the underside of the cloth, leaving an overhang of half of the number you are dividing by on all four sides (in this case 4½ inches); this extra space will allow you to create the scalloped edge.
2. Set your compass (on the underside of the cloth) to make a circle whose diameter is the measurement by which both sides of the rectangle are divisible (in our example 9 inches). Place the compass in one corner of the marked rectangle and draw a complete circle.
3. Start your next circle with the pencil side of the compass on the edge of the last circle and the pointer side of the compass on the edge of the marked rectangle; draw another circle.
4. Keep drawing circles until the entire perimeter of the rectangle is covered in touching circles.
5. Cut out the scalloped edge with scissors.
Originally published in the August 2013 issue of Parents magazine.