This is a 10 question (fill in the blank) quiz on multiplying and dividing powers of ten. Teachers can either use this quiz as a review by hanging the QR code answers around the room or school as a scavenger hunt, or they can use it as a standard pretest or posttest. I use this as a scavenger hunt to break monotony. Students come to me after answering EACH question. If their answer looks RESONABLE, I send them to check it using a QR scanner app. They really enjoy getting up and moving around. You could also color code the QR codes for differentiation as some problems are easier than others.