Granola Bar Math

After participating in the Camp Sylvan Eco Leaders of Tomorrow experience, the amount of waste that we generate at school began to nag at us.  But what to do about it?

St Bernard is so fortunate to have a snack program that runs under the direction of some very dedicated parents and grandparents.  We understood there were stipulations in what was served for snack and considered composting as an action project to extend our learning from Camp.

One wrapper measures 10 cm x 14 cm for a total area of 140 cm2.  

Usually we get granola bars about once a week.  That's 25 wrappers for our class...286 wrappers for the entire school.  So we wondered if it would be better to make our own granola bars since there would be no wrappers.  This would be quicker and easier to implement if given the go ahead.

Here's the amount of space 9 wrappers takes up on our carpet.

First, we asked our principal if it would be possible that our class make the snack for the school and if the snack program would cover the cost.  Mrs Daragon said yes!

Next, we set about determining everything we would need to find out to prove that this cooking adventure would be beneficial to the school.  After we brainstormed, we knew we needed to do a little math!

• length, width and height of the bar we currently received so that the homemade ones were the same size
• the area of 1 wrapper so that we could figure the total area of wrapper going into the garbage (the wrapper is NOT recyclable)
• the number of ingredients in the Kirkland brand of granola bar (the one that is purchased for snack program)
• the number of ingredients in the recipe we would use (we omitted almonds, flax, wheat germ)
• the cost of the ingredients needed to make the recipe for the school
• the cost of purchasing enough granola bars for the whole school
• the cost per bar if homemade (unit price)
• the cost per bar if purchased (unit price)
• the amount of time to make and pack for snack
• the amount of time to count the bars and pack for snack  

Finally, we booked the staff room during our Numeracy block and the students worked as partners to measure out ingredients and press the mixture into aluminum pans.  We then needed to refrigerate the bars so that they could be served the following day, which also happened to be "Boomerang Lunch" day where any garbage must be returned home so that there is no garbage generated through lunch and snacks.  Good timing!

The finished product!  Looks like a GIANT granola bar!

We heard many positive comments from different classes so we feel that in the cooking, we were successful. In terms of time, money and eco friendliness, we'll let you decide.  Check our findings in the pictures below and comment your opinion.  We can't wait to hear what others think!

~Miss Brooks