Your child will learn their equations in no time with these Subtraction Flash Cards from Duncan. Each card is made from a sturdy and durable material to stop them from easily bending or fraying. These cards will stay in great condition for a long time to come. Built for speed, you and your child will be able to go through these cards quickly. Each card is 4.7 by 2.75 inches and is the perfect size for speed and easy flipping. They also have rounded corners to give the cards some strength. Get this set for the child who struggles with these types of equations or get them all for the child who is just learning math. Each set is color coded so you do not get them mixed up with the others. You will be able to take these cards with you anywhere as they come in a convenient protective storage case. Start learning with these flash cards from Duncan.