en.wikipedia.org/wiki/Ice_cream_soda

www.yumsugar.com/National-Root-Beer-Float-Day-First-Black-Cow-485689

How much pop and ice cream for 60 people in 16 oz. cups?

I can't believe you continue to answer the STUPID questions about how much ice cream or root beer to order. FIGURE it our PEOPLE! It is SIMPLE MATH!

For the soda with these large cups, 6 per each 2 liter bottle, about 36 2 liter bottles. You might get a few sugar free for anyone who wants just a cup of sugar free soda- there will be some diabetics in a crowd this size.

If there is any one who can't do dairy, use a chuck of popsicle.

10/19/15 8-10 ounce cup, 1/4 cup ice cream, 3/4 cup (6 ounces) soda per kid. If there is any kid who can't do dairy, use a chuck of popsicle.

You can do this: get a gallon of vanilla ice cream in the brick form, 20 12-16 ounce cups, 3 2 liter root beers and 1 sugar free. Straws or plastic ice tea spoons or both. Can of spray whip cream if you want to get really fancy.

Set out the cups on a tray.

Starting your talk, whack the ice cream into 24 long strips by cutting 4 strips (3 cuts) down the length and 6 strips (5 cuts) across. This will give you 24 "logs". Point out that these fit in the cups, set aside- don't put in cups yet. Point out that if you put the ice cream in first the cups overflow with foam. Fill each cup over 1/2 w rootbeer, slip the sticks in, foaming starts, add the rest of the root beer to each to get a head of foam. Insert spoon/straw, top with whip cream if you use it, and take a bow.

For the soda with very large cups, 6 per each 2 liter bottle. You might get a few sugar free for anyone who wants just a cup of sugar free soda- there may be some diabetics in a crowd this size.

So a half gallon of ice cream would do 30+ servings, 80 1/2 gallons
A 2 liter root beer would do 16= 100 2 liters .

If I were serving this size crowd, I would rent a multi-spigot soft serve machine for the ice cream. Scooping this much ice cream is an invitation for a wrist sprain.

You do get that at even 2 minutes person, which is very fast, you are looking at 3200 minutes = 54 hours of serving time plus set up and clean up. Staff accordingly.

Use good root beer; Barq's or IBC are my preferences among the mass brands.

Make root beer ice rings
Using bundt pans or tube pans, make and freeze rings of root beer ice- fill pans about 1/2 full. With 125 people you will be using 10 2 liter bottles, or about 5 gallons, so get 2 extra and make 3-4 ice rings.

Pre chill ALL the root beer.

Put the ice ring in the bowl. Pour 1 2 liter over, add 1 cup 1/2 and 1/2, stir. Add 1/2 the second 2 liter, scoop on about 2 quarts of vanilla ice cream and pour he last of he root beer over all, creating the lovely foam. Stir gently and serve.

This will make 5 rounds, so You are looking at about 10 quarts of ice cream and 5 cups of half and half.

The half and half assures the creamy texture in every cup. The root beer ice rings are pretty and keep it chilled, helping to reduce excessive foaming.

Have at least 1 2 liter of sugar free root beer for any carb watchers.

if you put the ice cream in the cup first, the soda goes everywhere when you add it. Nearly fill the cup, flip n the pre-scooped ball of ice cream, then add just enough more soda to get a nice head of foam.