You can use these task cards at independent stations with snap cubes to have students practice subtraction as separating. Each card tells the student to build a certain number, subtract a certain number, and then find the difference. You can print them on card stock and laminate them for re-use. Included are 16 cards with subtraction problems within 20, and four blank cards.
If you would like the editable PowerPoint file, just send me a message. I saved it to PDF in case people downloading did not have the same font and for ease of printing, but I know how important it is to be able to adapt things to your classroom!