You've gotten lots of good advice here. The main thing is to never let your grandchildren think that something is only for boys or girls. Even if he wants a pink and purple quilt. Never say a word.

Make wonderful memories with him. And post a picture when he's done

Hay-don't think because he's a boy he shouldn't be interested! There are kids machine available for not much money, and if you can afford it, get him one! I would give my right arm (well, figurativly speaking, anyway) to have one of my sons or my DH even remotely interested! I envy those ladies on this board who's DH's quilt with them, pick their fabrics for them, make furniture for their quilting rooms, etc! I would start first before buying a machine for him, by letting him pick out a pattern and fabrics of his choice (give him a few to choose from) and sit him on your lap while you control the machine. Maybe let him carefully have his hands on yours while you run the fabric thru, just to give him the feeling of doing it. I have never taught someone young, but would love to! Be sure to take photos of him doing it!! Priceless! Sorry this is so long-I get a bit over the top with enthusiasm!

I have a 10 and 13 year gs's they are both doing mug rugs. My 10 yr old is a lefty and it is harder for him, but it saved their summer.