Durable, double-sided, write-on/wipe-off mat offers endless subtraction practice, with answers ranging from 0 through 10. The front features 110 equations, from 0 - 0 through 19 - 9, in random order. The back features all the same equations in numerical order, with the answer in light gray. Great for use at home, school or even in the car. Use with dry erase crayons or markers, sold separately. Not for use with regular markers or crayons. Use a paper towel or cloth to wipe clean. Can be fully cleaned with disinfecting wipes; or with soap, warm water, and a non-abrasive sponge. Dry completely before re-use. For ages 5 and up.