More from Amazon.com : http://www.amazon.com/gp/product/B00J8MBRTE?tag=purrfectcatdi-20 <br /> <br />Concrete Sliderule Volume Computer Calculator Lot of 6pcs <br /> <br />Calculates quantity of concrete required to fill a rectangular or round area <br />Calculates concrete required to fill cylinders and piers <br />This slide will calculate quantities up to 200 yards <br />Very easy to use---You are purchasing six calculators
