1966 and all that

The prices for representative goods in 1966 and 1996 provide an opportunity for discussing how to represent the changes which occurred over the 30 years. Possibilities include (among others):

1. subtracting to find differences (how useful is this?);
2. dividing to find how many times more expensive things were in 1996 than 1966;
3. finding the percentage increase in prices;
4. graphing the values to visually display the relative difference in costs of the different products.

When a criterion for comparison has been agreed, students can discuss the cost of which product has changed the most least or the most.

The information for milk provides an interesting challenge, and work with calculator and decimals may be helpful in making an accurate comparison [e.g., students might consider the price of a single ml or the change in the proportional price of a litre - 18.18c to 121.67c].

Where to next?

Student Questions for this article
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