Rounding was a tough skill for me to teach. I thought my kids "understood it" until I asked deeper questions and realized they didn't. So, I created a visual way to round numbers using a color coded interactive number line. Just this tweak some great practice opportunities really helped my students. Check out my rounding bundle which has everything you need to help your kids really understand rounding (to the nearest 10 and 100): http://mrk5math.com/RoundingMaterials | Mr Elementary Math