I've been asked to teach a cookie decorating glass for a weeknight activity at my church. I can't figure out how much icing I should have made up to decorate 200 cookies. We wanted to do half glace and half fondant.

My glace recipe is similar to this one that uses a lb. of sugar:

http://cakecentral.com/recipes/2119/toba-garretts-glace-icing

And my fondant recipe is similar to this one that uses 2lbs. of sugar:

http://cakecentral.com/recipes/3183/rhondas-ultimate-mmf

Do any of you use these recipes (or similar ones) and could you tell me about how many cookies a batch of the icing would decorate?

Thanks for any advice you can give me.