When I accidentally stumbled upon Wordle, a free and user-friendly web app that lets you group a bunch of words in different shapes, I fell head over heels in love with it!
The end result is so appealing to all types of learners that all my students were captivated every time I put it up on the projector screen. I would definitely use this for my math class to engage students as soon as they step into the classroom!
Reference
http://www.scholastic.com/teachers/classroom-solutions/2012/03/making-wordle-work-you-beyond-word-clouds-101