This is one of my students favorite math centers! I give them a storage clipboard with counters and a tens frame in the storage compartment. The students then walk around the room solving addition problems using their 2 sided counters. After they have solved the problem, they check their answer using the QR code provided. They record their answer on the recording sheet before moving onto the next card. In order to use this product please make sure you have downloaded a QR Reader app. There are many free options available for Apple and Android products. There are also 2 sets of recording sheets.