The students use any device with a QR code scanner to scan the codes. This can be an iPad, tablet, cell phone, or computer with a web cam. The codes are printed and posted around the room. Students visit the code, scan it, solve the word problem and record the answer on their record sheet. I am a technology coach and I have done this in several classrooms in 2nd grade. We did it with 12 iPads, so we paired the students and they took turns scanning the codes and worked the problems together. We had them each keep their own record sheet so each child was accountable for their own work. It was an excellent activity for having the students practice figuring out when to add and when to subtract as well as practice with regrouping. The activity went smoothly each time I did it.