"It senses activity kids. I do a 'feely' activity when learning the 'how we do science,' this idea organizes those 'touchy' things. I would leave the description off because I want my students to use their own words to describe the feel.
Hidden words for word work time. Kids write the word in white crayon, and then color over it with marker to make it appear. Could do with numbers- instead of markers using watercolors- students paint over to make number 'appear.