Comparing costs.

Every math textbook seems to have a lesson or two on unit costs.  Unfortunately, the prices given, even in new textbooks, do not reflect realistic prices where I live in the bush of Alaska.

A Tino's pizza costs around $6 to $8 each.  A pizza you can get at one of the grocery chains runs $21.00 for a $8.00 one on sale in town.  If I use the problems in the book, my students think something is off and don't  relate to them.

Anything frozen that is shipped to the village has the added cost of air freight.  This means I might be able to get a half gallon of ice cream for $5.00 in town but by the time its shipped out here, it costs $11 to $13.00.  Quite a mark-up.

Then there is the difference in prices locally.  For instance, a can of soda runs about $1.25 at the store but various groups buy a 12 pack at the store then resell the soda at $2.00 each.  It is a matter of convenience because they do not have to leave the building, drive to the store, and buy it.  I have no idea what a soda sells for in the lower 48 because I don't usually buy it. 

So in order to give students a real idea of cost comparisons, I have to use local prices.  There are five ways I can have students compare prices.

1.  Comparing different sizes of the same item to see if the cost per unit is consistent, or which one is the better buy.
2.  Rectangular vs circular pizza by weight, are they the same cost?
3. School prices vs city prices.  Our school runs a concession stand that is open during sports activities but not during the day because it sells junk food.
4. Comparing prices between the village and Anchorage so students get a better idea of the markup and cost per unit differences. This is easy to do because two stores in Anchorage do bush orders and have websites listing prices.
5. Compare prices between the two stores in town.  The stores are more like convenience stores but sell guns, bullets, freezers, and just about anything else a K-mart might sell.  I know that sometimes one store has a better price on eggs, milk, or cheese.

Its hard to teach comparing prices using price/unit cost since the store shelves do not have the tags you would normally find.  In a normal store, you might have several different brands or sizes of items but since the stores here are small and limited, they do not carry those tags.  This means my students do not have the opportunity to learn to read shelf tags the way most students do.

They do not get to see the tags showing the price/unit cost in different units.  I've seen two of the same type of product listed with price/product vs price/ounce which makes it much harder compare.  So I have to get creative for this type of comparison in the classroom.

What I do have available is the SpanAlaska Catalogue which allows people to order items in bulk.  I can have students look up various items and have them calculate the price/unit cost using the same unit.  I could have a friend take pictures, send them so I can show students how the tags normally appear.  I have to create the experience for my students so when they go somewhere with the shelf tags, they are educated and capable of using them.

Let me know what you think.  I'm interested.  Have a great day.