A B C E

Notes for Session 5, Part C

 Note 5 The transition from the physical representation of coins to a graphical representation (the line plot) can be challenging. It is easy to confuse the stacks of coins with the stacks of dots in the line plot, but in fact they are very different representations of the data. Each stack of coins corresponds to one dot on the line plot, and each dot on the line plot represents a stack of coins, rather than an individual coin (which it more closely resembles).

 Note 6 A typical method for solving Problem C4 is to keep the sum of the 9 values equal to 45. Often, people don't think of this in terms of balancing deviations. The purpose of Problems C5-C8 is to demonstrate that balancing deviations from the mean is equivalent to keeping the sum of the 9 values equal to 45. Again, making the connections between the physical, graphical, and numerical representations can be challenging. If you are working in a group, take time to discuss how the process of making changes to the line plot corresponds to the idea of equality of excesses and deficits explored in Part C. If you are working alone, take some time to think through this concept.