I developed this tool to help my students who could not grasp the idea of rounding to the nearest 10. We use a marker or chip to place on the number and then "roll" the chip down to the number. The chip always rolls downhill and if at the top goes over and down the hill. I have included one copy with just the 5's and 10's and one with all the numbers. It is my first upload and not as beautiful as most of the items you will find on TpT, but it works great and it is FREE!