Teachers are often wary about teaching measurement conversions through problem solving…we revert to mnemonic devices, tricks and chants rather than encouraging students to use the same problem solving strategies we have been trying to instill in them all year.
Why is it that we suddenly think it is more valuable to have students practice drawing the “Gallon Man”, memorizing how “King Henry Died Drinking Chocolate Milk…”, or chanting “Larger to smaller means to Multiply” than to provide them with experiences and strategies to help them make sense of the units and their relationships?
On her website www.mathcoachscoarner.com, Donna Boucher suggests encouraging students to use a 4-step problem solving process to develop their concrete understanding of the relationship between the units while incorporating the use of a reference sheet.
The steps are:
1) Write down what you are trying to identify from the story problem.
2) Identify the useful conversion from the reference sheet.
3) Draw a model of the conversion from the reference sheet.
4) Draw a model to represent the values from the story problem.
Here is her example of the steps for the following story problem: “Sue needs two gallons of lemonade. The lemonade she wants to buy only comes in quart containers. How many quart containers will she need to buy?”
Not only does this strategy help with making sense of story problems, it is also useful when students complete a 2-column conversion table. Read more at http://www.mathcoachscorner.com/2012/01/two-ways-to-approach-measurement-conversions/