1. GRADE 5 LESSON 2.5 ESTIMATE YOUR REACTION TIME OBJECTIVE: TO PROVIDE EXPERIENCES WITH ESTIMATING REACTION TIMES AND WITH USING STATISTICAL LANDMARKS TO DESCRIBE EXPERIMENTAL DATA

2. IN YOUR WORKBOOK Find Activity page 2 at the back of your workbook. Cut out the Grab-It Guage You will be using the Grab-it guage to measure the length of time it takes each of you to react to a stimulus. What is a stimulus? Find out the answer and add it to the word wall please.

3. USING YOUR STUDENT REFERENCE BOOK PAGES 121 AND 249 Conduct an experiment to estimate the average time it takes a student to react to having his or her hand squeezed. This is called Reaction Time. You will need to ‘borrow’ the whole class for this experiment. The experiment goes like this.. Practice first (once) then perform the experiment.

4. THE EXPERIMENT The leader and all the students, except the timer, hold hands and form a large circle around the room. As the leader, give the start timer and the signal to start timing as you gently squeeze the hand of the person on your left. The timer records the time on the board. The person on your left squeezes the hand of the person on his/her left. The squeeze continues around the circle until it reaches the leader, who calls out ‘Stop’. The timer records the stop time. Perform the experiment once more to ensure accurate data.

5. ELAPSED TIME Now that you have your data… You need to calculate the elapsed time. Elapsed time is the time it took from beginning to end of something. (in this case, from start of 1 st squeeze to end of last squeeze) Now we need to find the MEAN reaction time. Do you remember what Mean is? (Use your ISN’s to help you remember if you need to). How will we find this information? You may use a calculator if you wish. You will need to divide the elapsed time by the number of students who participated in the experiment. This will give you the mean (or average) reaction time.

6. ROUNDING TO THE NEAREST TENTH OR HUNDREDTH What was the mean reaction time of each student? How long is your number? Do you NEED all of the digits after the decimal point? If not, what number should you round to ? Tenths? Hundredths? Why did you choose that number? Discuss with your partners how you might round to the nearest tenth or hundredth.

7. ROUNDING TO THE NEAREST TENTH AND HUNDREDTH Use the hundredths digit to round to the nearest tenth. If the hundredths digit is 4 or less, round down..542.5.431538.4.4194949.4 If the hundredths digit is 5 of more, round up..45.5.551674.6.491.5 Use the thousandths digit to round to the nearest hundredth. If the thousandths digit is 4 or less, round down. If the thousandths digit is 5 or more, round up.

8. ESTIMATE YOUR REACTION TIMES. Using the grab-it guage and your workbook page 40. Read the directions carefully. Perform the experiment until you all have completed it. (record only your OWN data) Complete workbook page 41 using your data. Use the line plot to graph the results of the left and right hand reaction times. Use a separate color for boys / girls

9. MEAN, MEDIAN, MODE, RANGE… What is the typical reaction time of all students tested? What did you use to find this information? Calculate the mean, median, mode, range, minimum and maximum reaction times. Record these in your ISNs. Post your line graph on the wall for all to see…

10. GAME Play High number toss, decimal version Student reference book 321 Page 511

11. HOMEWORK, ENRICHMENT, EXTRA PRACTICE Homework – page 46 – Comparing reaction times Enrichment – page 48 – Interpreting Data (you may need to perform the second experiment with more students in your class to gather more data) Extra practice – page 47 – Decimal number line puzzles