Is this a good idea? Should i or should i not do it?

Ok i really like this boy and we're both shy. I can hardly talk to him because i get so nervous so he doesn't know how i feel. We're both taking the same summer school class and there is only a week of it left so i have to do something fast. I have no idea if we will have any classes together next year. I was thinking about writing him a letter and giving it to him on the last day of summer school. That way i wouldn't have to deal with the awkwardness during class if he doesn't like me. The letter would say......

dear X,

I know we hardly know each other and we haven't talked that much but i really like you. All summer i've been trying to talk to you but i get so nervous that i can't. I would really like to get to know you better so if you like me at all even a little bit here's my number *********. Call or text me if you want. If you don't like me then you can just ignore this or throw it away.

xo-Y

I didn't add our names or my number but this would be basically what it would say. Do you think this is a good idea? Should i say something different in the letter if i do give it to him? If you're a guy would you like to get this letter? Do you have any other advice for me?