Students measure the height of water in a beaker at five second intervals as it is being filled, being careful to leave the faucet on so that the water runs at a constant rate. They make a table of their results and generate a graph. They note that this is a linear function. Students investigate patterns of exponential growth with the calculator, such as compound interest or bacterial growth. They represent their findings graphically, noting that this is not a linear relationship, although in the case of simple interest, where the interest does not earn interest, the graph is linear.
Students obtain a table showing the depreciated value of a car over time.
They graph the data in the table and observe that it is not a straight line. Students compare different pay scales, deciding which is a better deal. They realize that the answer to this question depends on the number of hours worked, so they create a table comparing the pay for different numbers of hours worked. They make a graph and decide at what point the hourly rate becomes a better deal. Students predict how many times they will be able to fold a piece of paper in half.