Ready for some fun? Grab a copy of Ben Franklin and His Magic Squares to read aloud. Stop reading after it says, "Now Ben wondered if he could make the numbers [1-9, in a square] add up to 15..."
Give each student a set of 9 milk caps (I don't EVER throw them away!) to number, 1-9.
Challenge them to make a 3 x 3 array in which every row, column, and diagonal totals 15.
If they think they've found the answer, have them scurry off to write it down! (And hide it from everyone else!)
1. Not having all of the biggest numbers--or the smallest numbers--in the same row, column, or diagonal.
2. Setting some of the combinations in #1 and then working around those numbers.
3. Only moving a few caps at a time, especially if you're getting close.
You can also give the online version a try!