Using QR codes is a fun way for kids to use technology and adds another element to worksheets! For this activity, students can do 10 4-digit division problems with remainders and check their own work by scanning the code. If they get it right, they check "yes" and move on. If their answer does not match, they check "no" and try to fix their problem. Students love evaluating their own learning, and it teaches them self-monitoring and self-evaluation skills.
I use the QR scanner called "QR Code Reader" from the Google Play app store, but any QR scanner will work!