Let your students have fun working on math problems with this digital resource. It's a google sheet mystery picture activity on subtraction within 20 that your students will like. How It WorksYour students just have to solve the problems. Their answers will be automatically checked and a part of the mystery picture is revealed for every correct answer. What's Inside:Here's what you will get: 20 problems on subtraction: within 20Mystery Picture: JACK IN THE BOXAnswer Key is includedDigitalMyste