I saw that some of my students were working on Magic Squares in their math classes and I saw my in. Magic squares are a grid of 9, 16, or 25 boxes and when the numbers 1-9, 1-16, or 1-125 are inserted into the grid the total of each row, column and diagonal line is the same (15, 34 and 65 respectively).
I created verb and vocabulary activities that ask students to fill in the number of the correct answer in the grid and then when done they can add up the rows and check their work. This has been great for all sorts of verb forms and vocabulary (pictures work really well). The trick is to work out the number solutions on your own and to then fill in the grid. Students really enjoy this and it works great as a pair activity as well. Below is an example where students fill in the number of the correct subject/verb with the correct verb form.