Laminate a number ladder, cut small slits in top & bottom & add a pipe-cleaner with a small bead. Use the bead to slide up & down as you complete addition & subtraction problems (",). could do the same thing with a horizontal number line.
I absolutely love this idea for an alternative to the traditional ribbon or bow gift topper. Tracy, one of the new summer interns at The Crafts Dept. over at Martha Stewart Living, shares a DIY for this pop-up message “ribbon”,.