activity 35 BROWARD COUNTY ELEMENTARY SCIENCE BENCHMARK PLAN Grade K Quarter 4 Activity 35 Comparing Nonstandard and Standard Units of Measure SC.H.1.1.1 The student knows that in order to learn, it is important to observe the same things often and compare them. SC.H.1.1.3 The student knows that in doing science, it is often helpful to work with a team and to share findings with others. SC.H.1.1.4 The student knows that people use scientific processes including hypotheses, making inferences, and recording and communicating data when exploring the natural world. The activity also addresses these benchmarks from Quarter 1. SC.H.1.1.5 The student uses the senses, tools, and instruments to obtain information from his or her surroundings. SC.H.3.1.1 The student knows that scientists and technologists use a variety of tools (e.g., thermometers, magnifiers, rulers, and scales) to obtain information in more detail and to make work easier. ACTIVITY ASSESSMENT OPPORTUNITIES The following suggestions are intended to help identify major concepts covered in the activity that may need extra reinforcement. The goal is to provide opportunities to assess student progress without creating the need for a separate, formal assessment session (or activity) for each of the 40 hands-on activities at your grade. 1. Ask, Why is using a spoon ruler not the best way to measure your height? (Spoons come in many sizes. They are not a standard unit, so we can not make fair comparisons.) 2. Use the Activity Sheet(s) to assess student understanding of the major concepts in the activity. In addition to the above assessment suggestions, the questions in bold and tasks that students perform throughout the activity provide opportunities to identify areas that may require additional review before proceeding further with the activity. broward county hands-on science Quarter 4 353
354 activity 35 Comparing Nonstandard and Standard Units of Measure
activity 35 Comparing Nonstandard and Standard Units of Measure OBJECTIVES Students compare the use of standard units of measure with nonstandard units of measure. 1 Growth Chart (from Activity 33) 16 spoons, plastic spoons, assorted sizes* DSR How do we learn? The students predict their heights in nonstandard units use a measuring tool with nonstandard units to measure and describe their heights use standard units on a measuring tool compare measurements in standard units discuss the advantages of using standard instead of nonstandard units of measure SCHEDULE About 40 minutes VOCABULARY centimeter inch standard unit MATERIALS For each student 1 Activity Sheet 35 For each team of two 1 ruler, spoon (from Activity 34)* For the class 1 Class Height Chart (from Activity 33)* *provided by the teacher PREPARATION 1 2 3 Make a copy of Activity Sheet 35 for each student. Teams of students will need the spoon rulers that they made in Activity 34. Have extra plastic spoons available. Collect spoons of various sizes (such as a 1 /4 tsp measuring spoon, a soup spoon, a serving spoon, and a wooden stirring spoon). You will use these spoons in step 3 to demonstrate the problem of inconsistency when using nonstandard units of measure that vary in size. BACKGROUND INFORMATION In this activity students are introduced to standard units of measure. In the United States today, two standard systems of measurement are used: the U.S. customary system and the metric system. The U.S. customary system includes inches, feet, yards, and miles for length and distance; ounces and pounds for weight; and cups, pints, quarts, and gallons for volume and capacity. These traditional units are familiar to us and frequently used, even though conversions between units, such as feet to miles or ounces to pounds, can involve timeconsuming mathematical calculations. broward county hands-on science Quarter 4 355
1 A simpler system, based on the number 10, was developed in France during the late 1790s. This decimal system, called the metric system, is based on the meter (length), the gram (weight), and the liter (capacity). Because the metric system is based on the number 10, its units are easily converted by multiplying or dividing the basic unit by 10, 100, and so on. Metric units are also related to each other: 1 milliliter of water weighs 1 gram and fills 1 cubic centimeter of space. Most countries and the entire scientific community have officially adopted metric units as international standard units of measure. In the United States, metric measures appear on nutrition labeling on all foods, on many highway signs, and on some food packaging, such as soft drink containers. Guiding the Activity Gather the students around the Class Height Chart on the wall and review what it shows. Remind students that in the last activity they made measuring tools called spoon rulers for measuring length in spoon units. Display one of the spoon rulers. Distribute a copy of Activity Sheet 35 to each student. Explain that in this activity they will use the spoon rulers they made to measure their heights. Before measuring, though, they will act like scientists and predict their heights in spoons. Have students write their predictions on their activity sheets. Activity Sheet 35 356 activity 35 Comparing Nonstandard and Standard Units of Measure Comparing Nonstandard and Standard Units of Measure Answers will vary. Predict: I think I am spoons. Measure: I am spoons. Look at the Growth Chart. Find the number nearest the top of each animal. Write the number below. This is how the animal is. Measurements may vary Animal How? slightly. Students may use the abbreviation cm. 15 25 75 100 130 165 Additional Information It is a model of all the students heights in order. This is a prediction, not a guess, because students are using their prior experience with spoon measurements. Review that to predict is to state an expected outcome based on past knowledge, observations, and experiences.
2 Guiding the Activity Invite one student to find his or her adding machine tape segment on the Class Height Chart. Hold the spoon ruler against the wall on or next to the student s adding machine tape, with the zero point (green line) on the floor. Help the student use the ruler to measure his or her height in spoon lengths. Additional Information Show students how to read the ruler, matching the top of the adding machine tape to the nearest number on the ruler. 3 If the student s height tape is longer than the spoon ruler, help the class express and solve the problem. Distribute a spoon ruler to each team. Have students follow the procedure you modeled and use their spoon rulers to measure their adding machine tape strips. Tell students to record their actual heights on their activity sheets. When the class has finished, have each student report his or her height in spoons, saying, I am spoons. Point out that while this measurement helps us compare our heights with one another, a person in another classroom or another school might have different size spoons or no spoons at all. Show the class the spoons you collected. Ask, What do you observe about these spoons? Ask, Can anyone think of a better way to measure objects so that we can compare how long, wide, or they are? Students may suggest the following solutions: Borrow another team s ruler and place it above the first. Make a mark on the adding machine tape at the end point of the ruler and slide the ruler up to that point to start again. Hold up additional spoons to extend the ruler. Make an additional ruler or a longer ruler. For all of these solutions, students will need to count on from the end of the first ruler. If students suggest simply guessing, challenge them to try to find a way to take a measurement. You may wish to have students compare their predictions with their measured heights. How accurate were their predictions? The spoons are all different sizes. Point out that a person in another class or school who is 8 spoons may have been measured in little spoons, medium spoons, or big spoons. We do not know how he or she really is. A better way would be for everyone, everywhere, to agree to use the same size unit to mark off their rulers, as we did in our classroom. broward county hands-on science Quarter 4 357
4 Guiding the Activity As appropriate, read or review pages 13 and 14 from the Delta Science Reader How do we learn? Explain that a unit that all people agree on is called a standard unit. Write the words standard unit on the board. A standard unit is a measure that all people agree will always have the same size and name. Point out that the Growth Chart, posted next to the Class Height Chart, has two scales of units that are standard units. The Growth Chart has both metric and customary units. Use only one of these scales as you explore standard units of measure. For this discussion, use metric units (). Introduce the word centimeter and tell students that each line on the left edge of the Growth Chart stands for 1 centimeter. Gather students around the Growth Chart, point to the squirrel outline, and ask, How is the squirrel? Note: The animals pictured on the Growth Chart stand on four feet, not upright on two feet like humans. Heights of four-footed animals are typically measured at the shoulder, not the top of the head. Therefore the animals are positioned on the chart at the animals shoulder heights. For the purposes of this activity, either use the numbered unit nearest to the animal silhouettes or take measurements at the top of each animal silhouette. 358 activity 35 Comparing Nonstandard and Standard Units of Measure Additional Information Each long line on the right edge of the Growth Chart stands for 1 inch. The squirrel is about 15 units, or 15.
Guiding the Activity Point out that each centimeter is equal in size. Together, count the beginning at the bottom of the Growth Chart. Have students write the height (number and unit label) of the squirrel next to its picture on their activity sheets under How? Additional Information Write cm on the board. Tell students that these letters are a short way of writing the word. Students can copy these unit abbreviations when they complete the bottom part of their activity sheets. Then ask, How is the cat? How is the dog? Have students find the number nearest the top of each animal and use it to determine the heights of all six animals on the Growth Chart. Have students record these heights on their activity sheets. Help students recognize that they have now used a measuring tool with standard units to measure height. Ask, What is a standard unit of measure? Why would we want to measure with standard units instead of nonstandard units? Summarize that these standard units can be used and understood by people all over the world when they describe how a squirrel, cat, dog, or person is. R EINFORCEMENT The cat is about 25 cm (11 in.). The dog is about 75 cm (30 in.). The deer is about 100 cm or 1 m (40 in.). The cow is about 130 cm (52 in.). The horse is about 165 cm (65 in.). A standard unit of measure is the same size everywhere. Everyone, everywhere agrees on the name and the size of the unit, so other people can understand our measurements when we share information. Have teams work together to measure the heights of the Growth Chart animals with their spoon rulers. Record the data. SCIENCE JOURNALS Have students place their completed activity sheets in their science journals. C LEANUP Peel off the transparent tape and wipe the markings from the meter sticks with a damp cloth or paper towel. Return the blank meter sticks and extra plastic spoons to the kit. Leave the Class Height Chart and the Growth Chart in place. broward county hands-on science Quarter 4 359
Connections Science Extension Let students use the plastic spoons from the kit and various other spoons you collect to measure common classroom objects. (If possible, borrow spoons of several sizes from the school cafeteria for this extension.) Discuss the different measurement results that students get for the same object and how those results relate to the size of the spoons. Elicit that the smaller the spoon, the greater the number of spoon units in the measurement. Science and Language Arts Share with students the book Millions to Measure by David M. Schwartz (HarperCollins, 2006). This book discusses different units used to measure and explores how people measured items before standards were introduced. Students will discover how standard units of measure evolved over time. Add the science vocabulary introduced in this activity to the class Word Wall. Science and Math Turn the information gathered in the Science Extension above into a graph that shows how many spoons of different sizes are needed to measure the same object. Science and Health Length of Bulletin Board, in Spoons 360 activity 35 Comparing Nonstandard and Standard Units of Measure Students are introduced to a Growth Chart in this activity. Ask why they think this measuring tool is called a growth chart and not simply a height chart. (The heights of children are often recorded on growth charts because children are still growing, often very quickly. Their heights keep changing because they are getting er and er.) A child s height and weight are usually measured and marked on his or her growth chart as part of every visit to a healthcare provider. Children over the age of 3 are usually measured every year. The students in your class are probably growing at an average of 10 cm (2.5 in.) per year. After a growth spurt in their early teens, people stop growing er (girls between ages 13 15 and boys between ages 14 17). Grown-ups do not continue to grow er. 1 2 3 4 5 6 7 8 9 10 Plastic spoon Soup spoon Wooden spoon Mixing spoon