I just had to write to thank you so much for your wonderful books. We followed your directions with the flash cards, and have practiced every day. In only one month, she has learned all of the addition and subtraction facts. She can do them in the book and orally with the flash cards. It is truly amazing to see how she responds to the tricks. You can actually see the “light go on” in her eyes when she understands. We will keep reviewing these and start the multiplication book so she will be ready for 3rd grade. I have told many people about your books.