Making Mass Lemonade

      There are a ton of instances where we have to make mass quantities of lemonade or iced tea.  We run 3 booths at our town's Heritage Festival to help kids raise money for camp, and we serve both at our booths.  To dispense the lemonade or iced tea, we have many 5-gallon coolers.  We are using the one below this weekend to serve drinks to our kids working our Pancake Days event at the local mall.

     Inside the canister of mix, there is a plastic scoop with a chart of how many scoops make different quantities of lemonade.  

The problem: There is no way we are scooping out 16 scoops of mix for two gallons of lemonade.  We might need 5 gallons!  During a festival, we don't have time to scoop out 40 scoops of mix, especially when workers have to leave a booth to go to get the water, leaving the booth under-staffed.

How can we make this easier?!?!


Well, we notice from the label that a 1/2 scoop is a serving, as if anyone uses that amount.  And there are about 136 servings in the container.  I determine that 136 servings/container * 1/2 scoops/serving = 68 scoops/container.  Since 8 scoops makes a gallon, 40 scoops would make 5 gallons.


Well, half the container would be 34 scoops, less than it suggests for what we want.  We decide: let's try just half the can for five gallons of lemonade with junior high kids at our After School Break program.  Junior high kids can be the true judge of lemonade quality!  Sugar!  The can suggests it will be watered down a bit, but usually they tell you to use a bit more mix than necessary to keep you buying more.  When we tried out the half-can theory, the junior high kids approved!


So our rule now: just eyeball half a can of mix for a 5-gallon cooler.  Need 2 gallons for our smaller high school After School Break?  2/5 of 1/2 can. 2/5 * 1/2 = 2/10 = 1/5 = 20%.  Just eyeball about 1/5 or 20% of the can (or take the time to scoop out 16 scoops of mix).  If you want to go 1/4 of the can (1/2 of 1/2), just fill the cooler to 2.5 gallons (1/2 of 5 gallons) with water.


This is simple math, but the benefit is huge.


When junior high kids need more lemonade at their festival booth, they don't need to pull us away from what we're doing anymore to fill their cooler.  We can just tell them, "half a can of mix, fill 'er up with water."  Our high school kids or leaders can eyeball a certain amount of mix for a varied amount of lemonade.  We don't have to scoop anymore (thank goodness).  We save so much time now.


What I love is that the real-life problem starts with no particular correct answer. The goal is to just make the problem less of a problem.  Another thing: with all those numbers flying around, using labels is important for sanity's sake.


What you learn in class that applies:
1. Multiplying fractions
2. "Of" means to multiply
3. Factor-Label method (servings/container * scoops/serving = scoops/container)
4. Converting fractions to percents and vice versa
5. Making & testing a hypothesis (part of the scientific process)
And of course, many things behind the scenes such as problem solving and spatial reasoning.