I saw this photo of an aged McDonald's menu on Twitter. I spent about 2 minutes trying to confirm and the best I can find it is from 1974.
According the Bureau of Labors Statistics inflation calculator, $1.00 in 1974 is equivalent to $4.79 in today's dollars. So, multiply the numbers you see below by 4.79 and you will get those prices in today's money.
For instance, a $.65 Big Mac would be $3.11 today.
Using pricing information HERE, a Big Mac today is priced at $3.99 (not as part of a combo meal). This means the price of the Big Mac has increased 28% over the general rate of inflation for the past 40 years.
A fun-ish class excercise could be to do like I just did above and look at how, after adjusting for inflation, prices have changed over time.
Questions to ask would be how has portion size changed? Quality and composition of the food? Competition in the marketplace?
Here is a recent one. Big difference, eh? The simple life no more.