This activity is designed to extend students' understanding of different types of patterns (numerical, alphabetical, & geometric). The activity is intended for students to work in cooperative pairs and design their own original pattern for their fellow classmates to solve. I always recommend for them to be creative and make it a challenge; however, the numbers should never be ridiculous where someone cannot solve it mentally.
When assessing your students, have them explain to you what the pattern is and share the answer with you. Once you have approved their work, they are to write the answer on the reverse side of the worksheet so that when they are on display, whoever is attempting to solve can lift up the paper and see the final answer. That being said, do not tape or pin the bottom part of the paper to the wall or bulletin board.
Encourage your students to have fun with this and add an element of artistic creativity. I also recommend spending time in class to allow students to present their "code" to the class.
I always use this activity prior to Back-To-School Night and have them on display in my classroom. The students love the idea of challenging their parents and the parents have fun finding their children's work and attempting to solve!