Your children will quickly become skilled mathematicians with this subtraction learning mat! This durable write-on/wipe-off mat provides endless hours of subtraction problems for your children to practice. Great for at-home, for a fun meal-time activity, or take it on-the-go to use in the car or while eating out. Ages 5+. Use with dry-erase crayons. Do not use regular crayons or markers. Use a paper towel or cloth to clean dry-erase crayon marks. Mat can be fully cleaned with disinfecting wipes, or with soap, warm water, and a non-abrasive sponge. Dry completely before re-use. 1 Double-sided mat.