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It's Time to Make Time! (Grade 3-4)

Master Teacher

Vivian Johnson

Overview

This lesson will allow students to explore the evolution of time measurement, to understand the relationship of sunrise/sunset to length of daylight, and to collect data and calculations to determine length of daylight.

SC Math/Science Standards Met

Math Achievement Standards—Grade 3:
Area V—Measurement
Strands: A, G

Math Achievement Standards—Grade 4:
Area V—Measurement
Strands: A, G

Science Achievement Standards—Grade 4:
Area III—Earth Science

Strand 2: a, c, e

Learning Objectives

Students will be able to:

list, draw, and create examples of technology involving time measurement
describe how the earth's rotation on its axis produces day and night
record and graph sunrise and sunset patterns over time
calculate elapsed time

Materials

sundial—stick
water clock or sand clock—plastic tubs of various sizes, nail for making hole, stand to hold tubs, water, sand, stopwatch
pendulum—string, weight, stopwatch
potato clock—kit
digital camera, video camera

ITV Series

Inquiring Minds: Classroom Edition, Lesson 5, "Why Do Clocks Go Clockwise?"

Previewing Activities

Introduce the lesson by reading from the beginning of Alice in Wonderland to where the rabbit says, "I'm late, I'm late, for a very important date!" Ask students, "What technology keeps us from being late? How have people told time since the beginning of time?"

Focus for Viewing

To give students a specific responsibility while viewing, students will complete a "History of Time Measurement" worksheet (Activity Sheet 1) during the programmed pauses.

Viewing Activity

Start the video at the end of the introduction segment where the narrator is in the woods back in time and begin where the narrator says, "Way back around 3000 BC or so, the main method of keeping track of time was what I'm standing on now, the earth."

Pause the video when the narrator has just explained the sundial or shadow clock and says, "What the shadow tells you is how much daylight you have left, a handy piece of information if you need to find shelter for the night." Ask students to label and draw this first example of a time-measuring instrument on their work-sheet. (shadow clock or sundial)

Skip the video through the clockwise explanation and begin where the narrator says, "Now where was I? The sundial was used by many societies to keep time." Pause the video after the narrator has explained the water clock and says, "A fairly decent method, unless you lived in a cold climate. Then time seemed to stand still." Ask students to label and draw the time-measuring instrument. (water clock)

Continue the video and pause when the narrator has explained the sand clock and says, "Hate to be the guy who has to turn that thing over when it's done." Ask students to label and draw this time measurer. (sand clock)

Continue the video and pause after the narrator has explained the 14th-century mechanical clock of wheels, gears, and springs, and says, "Because of their material, no two clocks kept the same time, and that's what it's all about—consistency." Allow students to label and draw the timepiece. (14th-century mechanical clock) Their drawing should show wheels, gears, and springs.

Resume the video and pause it after the narrator has explained the need for a regular and constant cycle—the pendulum and its relation to gravity (the power source), and the narrator says, "The final thing you need is a display, and there you have it—a clock. Is that the correct time?" Allow students to label and draw this timepiece. (pendulum clock)

Continue the video and stop after the narrator has explained why the pendulum is not an accurate timekeeper and explains about quartz and its vibrations and says, "A quartz clock is ten times more accurate than a pendulum clock." Allow students to draw and label this technology. (quartz clock)

Post-Viewing Activities

1. Students will make timekeepers. Divide students into groups. Each group will create (see materials) a timekeeper as seen in the video presentation and, using a digital or video camera, present their creation which actually measures a unit of time. These experiments will allow students to see the difficulty of regulating the measurement of time.

a. Sundial. Take a picture showing the shadows at different times.

b. Water clock. Videotape the clock measuring one minute of time.

c. Sand clock. Videotape the clock measuring one minute of time.

d. Pendulum clock. Videotape the clock measuring one minute of time

Action Plan

1. Students will keep a log recording sunrise and sunset. They can use different sources, such as the daily newspaper and the Internet site Accuweather.com.

2. Students will calculate the length of daylight using the above data. The length of daylight will be graphed throughout the school year, perhaps graphing once-a-week data as the third-grade Everyday Math textbook series recommends. This series also recommends using a different color to graph each season's length of daylight.

Extensions

1. Technology:

A Walk Through Time - to explore the history of time
Countdown- to calculate the seconds, minutes, or days until the millennium or your birthday
Local Times Around the World - to find out what time it is anywhere in the world by continent/country/location
Greenwich Mean Time - to find Greenwich Mean Time
Time Service Department - to find the USNO Master Clock Time
Sundials on the Internet - to find sundial information
AT&T Laboratories to see a live picture of a sundial

Activity Sheets (PDF)

Activity Sheet 1