All you can eat for 10 cents

The history of the Dairy Queen franchise began with this ad in Illinois in 1938: All the ice cream that you can eat for only 10 cents! 
We know that 10 cents was worth more in the past, but was it worth enough even then? How much would that all-you-can-eat ice cream special cost today? In this updated activity, there are two parts:

In Part One, students of all ages (Grades 5 & up) use fractions and unit conversions to estimate how much ice cream one person could eat and what a fair price would be today. 
In Part Two, older students (Grades 8 & up) will use the Consumer Price Index and inflation to find what the deal would cost in today's dollars, decide whether Sherb broke even, and more. 

⏰ Minimum 30 minutes

🍦National Ice Cream Day is celebrated globally on the third Sunday of July.