Sharpies and markers generally run out waaay quicker than pens or pencils. They also dry out if you're not careful, and dry out temporarily if you use them for

Sharpies and markers generally run out waaay quicker than pens or pencils. They also dry out if you're not careful, and dry out temporarily if you use them for more than a few minutes at a time. Crayons just aren't dark enough, and are too wide. Accurately reading numbers and symbols written in crayon at a normal handwritten size is not something I want to do. Not to mention the constant sharpening.