Every day in Math, my students complete this activity as an opener. On Monday, they complete the puzzle you see here. I have a copy of this one without any numbers. If you would like this, just email me and I will send it to you free of charge. (or you can just print the original and white out the numbers to hand-write your own in-its up to you!)
I change the problems every week so the clues are different. After the first week, students will use the previous week's magic number as the first number in the "start here" circle. You can make this activity as difficult or easy as you want.
On Tues-Fri, students complete a second page as they start math class each day. I also modify the questions on this weekly to ensure practice in different skills we learn in class. You can find this document in my store under the title "Magic Number Part 2".