Q Code reader task cards. This set of 12 cards gives students the opportunity to practice subtraction with borrowing, and borrowing across zeros. My students love these q code tasks cards. In fact I even have students ask to use the cards over the weekend!!! What a great way to motivate students. I use a free code reader app and let the students use my phone but many kids will bring in their own I Pods and download the free app to play the with the cards.