Lesson Objective: Students will learn how to enter data in their TI-73 graphing calculator.   Supplies and Materials TI-73 calculators Activity Sheet Overhead Projector Overhead TI-73 Calculator   Help students follow the 10 steps outlined on the activity sheet. Students will collect data from the three given pictures, record it in the table, extend the table, enter it in the L1 and L2 on their calculator, set up a statplot, set an appropriate window, and graph the data. Students should record a picture of their graph before moving onto the next exercise. After students have entered the data in their calculator, recorded a copy of their graphs, it would be appropriate to discuss differences and similarities between all the graphs they obtained. Students might notice all graphs increase the first, second, and fourth graphs increases at a steady rate the third graph is not a straight line the third graph curves up as it increases