DOES IT MEASURE UP?

MASTER TEACHER  Colleen McGran

GRADES   K-2

OVERVIEW
This lesson provides students practice with using metric measurement.  They will use weight, length, and capacity to measure concrete objects.  They will practice estimation prior to measurement.  Students will apply this knowledge to compare prices of items to determine if they are getting a "bargain" by purchasing certain products. 

ETV SERIES
Mathica's Mathshop:  #204 Big Business

LEARNING  OBJECTIVES
Students will be able to:
*compare weight to determine the best price.
*measure themselves in centimeters and order their height from tallest to shortest.
*measure capacity using a liter and compare different shape containers.
*examine cost versus quality in popcorn.
*estimate weight, length, and capacity.

MATERIALS
per class
hot plate
pan 2 qt. with lid
oil (enough to cook three batches of popcorn)
three brands of popcorn
science board labeled with the scientific method
graph paper - one sheet
markers - three different colors to graph results
paper to write parts of the scientific method
conversion chart labeled:
1000g=1kg
10cm = one new crayon
1 cm = width of little finger
100 cm = 1 meter
 

Center 1
kilogram scale
10 pre-measured bags of jellybeans and popcorn (100 g in each bag)
one bag of jellybeans and popcorn weighing1 kg
25 small zip-loc baggies 

Center 2
cusinnaire rods
10 long rods taped together lengthwise
yarn
piece of butcher paper labeled to 200 meters

Center 3
three liters colored water
empty containers of mouthwash, soda, water (at least 2)
funnel

VOCABULARY
bargain  getting the most for the money
gram (g)  metric measurement for weight
kilogram (kg)  1,000 grams = one kilogram
centimeter (cm)  unit of measurement used for length
meter (m)  100 cm = 1 meter
liter (l)  unit of measure for liquid
capacity  amount of liquid a container will hold

PRE-VIEWING ACTIVITIES
Give students a grocery list with the following items listed on it:  3 liter bottle of soda, 1 bag of popcorn, 1 package of jelly beans.  Ask students how they know which brand to buy to spend the least amount of money.  Guide them to answer that they could compare weight and price to spend the least amount of money. 

FOCUS FOR VIEWING
To give students a specific reason for viewing tell them, "Today you will watch a video in which Mathica is doing business with a peddler.  I want you to watch for how Mathica uses knowledge of measurement to prove the peddler wrong and receives the most for her money."

VIEWING ACTIVITIES
Begin video when "Big Business" appears on the screen. Pause when Mathica says, "What's the best buy?"  and the words appear on the screen.  Set out the bags of jelly beans labeled 100g and priced at 3 gold pieces out and 1 kg bag of jelly beans priced at 35 gold pieces.  Ask the students how we can tell which is the best buy?  Lead them to weigh the 100 g  bags until they reach 1 kg .  Add how many gold pieces that would be.  Compare to 35 gold pieces.  Ask which is the best buy?  (the 100 g bags because they would cost less)  Resume video.  Pause when Mathica says, "The length of Rip VanWinkles cane" and places it on  her head.  Using cuisannaire rods display a unit, a long, and 10 longs taped together lengthwise.  Ask the students to find something in the classroom about as long as each.  (paperclip, marker, game board, answers and items will
vary)  Resume video. Pause when Mathica says, "How tall am I in centimeters?"  and the question appears on the screen.  Ask the class about how long the cane was? (answer, one meter) Guide the students in estimating how tall Mathica is in cm using this information.  (answer, about one and a half canes tall)  Resume video.  Pause when Mathica says, "The question is, can both of these bottles hold a liter?" and the question appears on the screen.  Ask students to predict how Mathica and the Peddler can check to see if both containers hold a liter?(answers will vary, they could measure by pouring the liquid into containers marked 1 liter)  Resume video.  Stop video when Mathica says, "I'll never be anything but what I am, little." and Mathica is holding up her hand showing little and the peddler has just laid out 18 gold pieces.

POST-VIEWING ACTIVITIES
To give students hands on experiences with measurement similar to the video, rotate small groups through the following centers. 

Center 1:  Weight
Using the kilogram scale let students weigh popcorn and compare to pre-measured bag whose weight is 1 kg.  Put prices on each 100 g bag and 1 kg bag. Ask students which is the best buy.  Do the same with jellybeans that are pre-measured.

Center 2:  Length
Estimate how tall each person in the group is in cm.  Check their estimation by measuring on the chart.  They can use 10 longs taped together to check their answer.  Use a piece of yarn for each child.  Cut the yarn to equal their height.  Have the group tape their lengths of yarn in order from tallest to shortest.

Center 3:  Capacity
Using the containers of mouthwash, soda, and water have students practice measuring one liter.  Have them determine which containers are one liter, more than one liter, or less than a liter. 

Reveal the popcorn brands and their prices  from Center 1.  Ask students which will pop more?  Have them hypothesize which will pop more.  Count out 100 kernels from each brand.  Pop them separately for one minute.  After one minute count to see how many unpopped kernels there are.  Record the experiment using the scientific method.  Include the problem, hypothesis, materials,
procedures, observations, and conclusion.  Create a graph for each brand recording the number of unpopped kernels.

ACTION PLAN
Visit a grocery store to compare the price of pre-packaged food and food that can be bought by the pound, or kilogram.  Check to see which one is the best buy.
Create a conversion chart for measurement to be used at home while measuring.

EXTENSION ACTIVITIES
Writing
"If I were the size of a Giant..."  Have students tell how tall they would be if they were a giant and write what they would do.

Math
Do the same center activities using standard measurements of inch, yard, quart, and pound.
Measure other items in the classroom in centimeters and meters.
Weigh items used in the classroom.  Find as many things that weigh 100 g. and 1kg.

Social Studies
Economics:  Ask students why they should compare prices when they buy groceries.  Discuss the price of beans in the video and how they differed. 
Compare the price of popcorn from the science experiment.  Discuss whether the price made a difference in they way the popcorn popped. 
Have students discuss why they should know how to measure and to check for the best buy.

Technology
Ask Dr. Math about measurement at http://mathforum.org/dr.math/drmath.elem.html

Updated:  April 01, 2008