* 116 flash cards, including one for each fact family for addition and subtraction with sums from 1-20
* Students practice relationship between addition and subtraction (covering the top corner shows addition problems, covering a bottom corner shows subtraction problems)
* Big size (one card per page) for group games or whole class review/practice
* Great for math centers
* Easy at-home practice with math facts
* Black and white pdf document is easy to print (8 1/2 x 11). Print on card stock and laminate so they last for a long time!