Ten is too young to run a chainsaw. I believe a kid has to have not only the maturity and common sense to do so, and be able to learn proper procedures and safety (and retain them in the brain!), but have the physical capabilities to run that saw as well. My oldest two boys (ages 23 and 20) have the physical capabilities but I would not trust either one of them to pick up any tool from the correct end, let alone operate it. The retention of safety and operating requirements just isn't there, because they simply have no interest. On the other hand, my youngest son, age 11, is certainly interested, but not physically capable yet, in my opinion. I was 13 before my dad would even let me run a saw, and that was limited to controlled conditions, which amounted to bucking small logs on a sawbuck with no chance of pinching or kickback. I do have the 11-yo using power tools in my woodshop, but a drill, sander or jigsaw does not equal a chainsaw. I haven't even mentioned my daughters - the 19-year-old has no interest, and due to some physical limitations probably can't anyway. The 9 year-old is a girly-girl and it's hard enough just to get her outside to stack wood. Who knows - maybe she'll wind up being the woodworker and sawyer out of all my kids.