What's On Your Plate?: Sugar and Coke

Lesson
Personal Student History
Each student records the number and kinds of sodas they had the week before. Do this before because some will have trouble admitting they drink soda after the lesson.
Collect data for class.

Portion Size
Hold up antique 6.5 ounce glass bottle.
Tell story: When Ms. Tanner was a kid she used to ride her bike to the gas station and buy a coke. This is the size that was available in machines (6.5oz). She had to drink it at the gas station because the bottle was re-used: sent back to the bottling plant, cleaned, sterilized, and re-filled.

Ask student to read ounces on the old bottle…6.5 ounces. Go to bottle now found in machines…20 ounces.  You might not want  to say how amny ounces it holds yet.
 
Ask how many small bottles would it take to fill up the larger  bottle in the machine today? Students guess.
Pour water into the 6.5 oz bottle; then pour water into 20 oz. bottle. Refill the 6.5 oz. bottle again and repeat until 20 oz. is full. Over THREE times bigger.
What does this say about portion size? Students ususally have lots to say.
Portion size has changed. Seriously changed.

Complete Sugar in Coke Chart
Now we are going to see how much sugar is in soda.
In the 12 ounce can there are 9.5 tsp of sugar.

This is starting point. Figure out how many teaspoons of sugar is in one ounce of coke. We call this the UNIT rate … the amount of sugar for ONE ounce. Finding the unit rate is a 6th Grade California Math Standard.
9.5 tsp         x tsp
12 oz      =   1 oz

Kids do the math: .8 tsp/oz
Scoop out a teaspoon of sugar and then approximate .8 teaspoons so kids see what .8 tsp looks like and that it is almost a one to one ratio.

Hold up each of the 7 bottles telling how many ounces each bottle has so kids see range of bottles.

Review chart so kids see they are calculating the amount of sugar for one bottle, as well as the amounts of sugar if they drank one of the bottles every day for a week, month and year.

Students complete Sugar and Coke Chart.
We usually break here and complete the next session the following day.

Measure Sugar
Each table, which is a group of 4 students, is given:
One Coke bottle
Bowl with about 4-5 lbs of sugar
3 large Ziploc plastic bags
Index cards to label bags
4 teaspoons
Quarter cup (12 tsp) and half cup (24 tsp) measures for larger bottles
Sugar and Coke Charts completed on previous day

Start with amount of sugar in one bottle. Kids spoon it out into plastic bag.
Label bag using index cards inserted in bags so kids are not writing on bags and bags can be re-used.

Kids at table go on to second bag and spoon out how much sugar a student would get if s/he drinks one soda per day for a week. They label the bag.
Labels include:
Table number
Size of bottle
Amount of sugar in teaspoons and pounds when useful
Time period…day, or week, or month

Continue to third bag if possible (some take too much sugar) to see amount of sugar if s/he drinks one soda per day per month. Label that one.
For the year, students will only be able to fill out on data sheet.
Calculate teaspoons for the year and convert to pounds. Teaspoon to pounds conversion is on sugar container from store.
113 tsp= 1 lb
Each table shares their findings and displays bags of sugar for their bottle with class.
On the back of hand-out students write a reflection addressing changes in portion size and in the amount of sugar is a coke.  See sample of student work in attached files.

Thanks to people at CanFit for the inspiration.