Help students visualize and calculate elapsed time with a flexible ruler that can be made into a circle. Place the sliders at start and end times, then count the time in between the markers. Hours are divided into five minute increments marked with dashes and 15-minute increments are also noted. 5 rulers per pack. Measures between two increments of time. Has slits at end of ruler so it can be made into a circle. Write on/wipe-off. Unfolded ruler measures 17.5” x 1.75”, Rolls into a 5” diameter. Includes suggested activities.