I have a circular saw and I used it to cut out this round piece of plywood but what I really could have used is a saw that cuts circles, like a jigsaw or maybe a band saw. We have these big flower pots out back and rather than fill them with top soil I decided to “short shelf” them. That’s a grocery store term. I broke this stick and jammed it down the pot until it stuck to both sides and then brought the stick in the garage to measure the diameter of the circles. Then I split the distance and pounded a nail in the center. I tied some string around my pen and the other end around the nail and swung my circumference. And then in a series of short cuts I whacked out the circles with my circular saw.