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.
Create this DIY Slider Bag calculator for a fun way to answer your math questions! Great way to put number lines at your students' fingertips. Great for students with special learning needs. Very visual!