Sidewalk Chalk. Create a huge splash of color on your sidewalk or driveway with Crayola Sidewalk Chalks. Draw big, colorful art outside in a variety of colors or use these chalks in Crayola's fun Sidewalk Chalk Tools (not included). This package contains twenty chalks in twenty colors. Conforms to ASTM D4236. Recommended for children ages 4 and up. WARNING: Choking Hazard-product can make small pieces. Not for children under 3 years.