Memory exercise. Make it clear that this is an experiment and not a contest. Each student's honesty is necessary for valid results. Pass out the telephone number activity sheet to each student.
Put the following phone number on the board: 638-1752. Direct the students' attention to the number. Have the students recite the number three times. Erase the number. Instruct students to write the number down from memory on the activity sheet.
Write the next phone number on the board: 736-2841. The students will recite this number three times as well but will be interrupted with distractions (you may assign some students to tap on the desk, drop their books on the floor, talk, you may have another teacher come and knock on your door at this time). Erase the number and instruct students to write the number down from memory.
Have each student recite his or her own phone number three times (if they do not have a phone they may use a phone number that they know well such as parent's work number or grandparent's number.) Include the arranged distractions during their recitation. Have them record their number on the activity sheet.
Finally, write the following three phone numbers on the board: 573-4825, 362-9547, 821-5297. Have the students recite the entire list three times and then erase the board. Have students record the three numbers on the activity sheet.
Go over the correct phone numbers. Have the students check off if they got the number correct. Poll the class and have each student record the number of students in the class who got that number correct. Have the students answer the questions on the bottom of the page. A discussion of the results will lead to the characteristics of short-term and long-term memory.
Use the handout of short-term memory and long-term memory or disseminate this information through note-taking. In particular, point out that short-term memory is highly vulnerable to distraction (Hopefully exercise #2 demonstrated this fact), and short-term memory has a limited capacity (the reason why most students could not remember all three phone numbers).