Saturday signage: Ice-cream brain freeze

Every now and then, you come across a sign that tries very hard to impart enough information to be sure of absolute clarity. Usually, this coincides with a severe case of Too Much Information (although thankfully free of biological details). Result, everyone is happy until they start looking at the fine print. Here's a perfect example - fine right up until the last two lines...

So, 1 scoop = 2 scoops? What the hell do you do for an encore? Divide by zero?