Easy Wipeoff Subtraction Author:Dr. Ed Tronick The Easy Wipe-off Subtraction Workbook will help children build confidence while mastering basic subtraction facts, beginning with smaller numbers and building to larger numbers. The basic equations from 1-0 to 10-10 are included. Make sure the child understands the directions before beginning each page. Answers can be written in crayon, dry era... more »se marker, or washable marker. The answers can be easily erased with a clean, dry cloth or tissue, so that each page can be practiced again and again.« less