Answer:
well first you need to add all of it up which is 1 and 6/4 or 2 and 2/4
which is one lemony orange slush.
then if you do it again you'll just have to *2 every ingredient and that would make:
6/4 or 1 and 2/4 cup of orange juice
6/4 or 1 and 2/4 cup of club soda or seltzer
2 tablespoon lemon juice
so you would need 1 and 2/4 cups of orange juice.