1 Measuring Length Guided Activity

Home , Decametre, Decimetre, Kilometre, Millimetre

05a-NEM6-TG-ON-CH05a 7/19/05 7:49 AM Page 13

CHAPTER 5 STUDENT BOOK PAGES 142–143 1 Measuring Length Guided Activity

Goal Select an appropriate measuring unit.

Prerequisite Skills/Concepts Expectations • Know metric length units • select and justify the appropriate metric unit to measure length or distance in a (kilometre, metre, centimetre, given real-life situation millimetre).

Assessment for Feedback What You Will See Students Doing… Students will When Students Understand If Students Misunderstand • select an appropriate unit for measuring length • Students will select a unit of appropriate linear • Students will choose an inappropriate linear unit of measure for a specific context. measure. Provide these students with rulers, metre sticks, or measuring tapes so they can measure different items, long and short, and become familiar with each unit of measure (kilometre, decametre, metre, decimetre, centimetre, and millimetre). Students can also look at the different units of measure on their rulers and compare the sizes of the different units. This will help them visualize the size of each unit of measure.

Preparation and Planning Pacing 10–15 min Introduction 10–15 min Teaching and Learning Meeting Individual Needs 20–30 min Consolidation Extra Challenge Materials •Rulers, tape measures, metre sticks • Students may be challenged to design a poster to help classmates choose •Optional: road map or atlas; an appropriate unit for measuring length. They could show examples with smaller items to measure graphics of things that can appropriately be measured with specific units. •Optional: rulers or tape measures marked in cm and mm, 1/pair • Students may want to share information about Western rain forests with the class. Direct these students to the following Web sites: Masters •Optional: Chapter 5 Mental Math p. 55 • www.nps.gov/olym/edurain.htm •Optional: Measuring Length • http://curriculum.calstatela.edu/courses/builders/lessons/less/biomes/ Cards (Master) p. 62 rainforest/temp_rain/temprain.html •Assessment: Problem Solving/ Thinking Rubric, Masters • www.arbutusartsofthegulfislands.com/ftree.html Booklet p. 8 Extra Support Workbook p. 42 • Provide students with Measuring Length Cards (Master) p. 62. Have Key Question 8, Application of Learning students cut apart cards and match cards with the name of an item to be Assessment measured with the appropriate unit. Ask students to explain their reasoning of Learning for their choice of unit. Alternately, students can work in pairs to quiz Question each other on matching the cards. Mathematical Reflecting, Selecting Tools Processes and Computational Strategies, Representing, Communicating

1. Introduction (Whole Class) ➧ 10–15 min Display a road map or atlas and a number of smaller items of varying sizes. Explain to students that in today’s lesson they will be selecting appropriate units for measuring length. If desired, distribute rulers or tape measures for students to use as reference. Although no actual measuring is required in this lesson, having a ruler marked in millimetres and centimetres may help students remember the relationship between the units. Sample Discourse “Let’s think about measuring length or distance. What is the most appropriate unit for measuring distance?” • A map or atlas can tell us distances from one city or place to another. The distances are measured in kilometres. • One kilometre is equivalent to 1000 m. “Sometimes personal referents, or measures to which we can relate, gives us a sense of how far 1 km is. What route in our community is about 1 km?” • It’s about 1 km from my house to the school. • It’s about 0.5 km from my home to the school, so if I walk to school and back, that’s about 1 km. “What is the next main smaller metric unit for measuring length? What could we use as a referent?” • The metre is the next main unit. A door is about 2 m high and a bit less than 1 m wide. • A section of sidewalk is a square about 1 m each side. “What is the next smaller metric unit for measuring length and what could we use as a referent?” • The centimeter is the next unit. My finger is about 1 cm wide. 2. Teaching and Learning (Pairs) • My eraser is about 1 cm wide. ➧ 10–15 min “What is the smallest metric unit for measuring length that we use? What could we think of as a referent?” Ask students to turn to Student Book page 142. As a class, • The millimetre is the smallest unit we use for measuring length. read the context and the central question. Encourage students I stacked up 10 dimes and then measured the height. It was to examine the photos carefully for referents, as many will about 11 mm, so the thickness of 1 dime is just slightly not have personal experience with forests. Inform students more than 1 mm. that the arbutus is a deciduous tree that is never without Tell students that these referents, and any others with leaves—new ones grow as old ones drop off. which they are familiar, will be helpful to them in this lesson. Ask students to explain why they think James might want to use decametres to measure the length around the Introduce students to the decametre. Tell them that a base of the tree. decametre is equivalent to 10 m. Ask them to use one of Have students work in pairs to complete prompts A to F. their referents to describe 1 dam. Before completing the Reflecting questions, gather as a whole • One section of sidewalk is 1 m wide. Then 10 sidewalk class to share solutions. This will provide an opportunity sections are 1 dam. to assess students’ ability to select the appropriate unit Remind them that in this lesson, they will be learning of measure. about selecting appropriate measuring units. Reflecting Here students reflect on the metric units of linear measurement and their use. Allow time for discussion before having students record their answers.

3. Consolidation ➧ 20–30 min For intervention strategies, refer to Meeting Individual Needs or the Assessment for Feedback chart.

Closing (Whole Class) Have students summarize their learning considering a different context and relating it to metric units of linear measurement. For example, they might respond to the following prompt: “We can measure the length of different things in our classroom using different units. • Some things we can measure in kilometres are …; some things we can measure in metres are …; some things we can measure in centimetres are …; and some things we can measure in millimetres are …”

you measured them in millimetres then the number would be big. If you measured something really small in kilometres, you’d get a very small number with lots of decimal places. 4. a) For example, I would use metres to measure the height of a room since the height is longer than a metre stick. b) For example, I would use millimetres to measure the thickness of a window since a pane of glass is thin. Key Assessment of Learning Question (See chart on p. 16.) c) For example, I would use kilometres to measure the distance since you would have to drive to measure it. 5. a) For example, to measure the height of the trees I would Answers use centimetres if the trees are really young and tiny. If the trees are at least 1 m tall, I would use metres. A. I would use metres to describe the height of the trees. b) For example, to measure the length of the leaves For example, the tree looks too tall to measure it in I would use centimetres since most leaves are at least centimetres. Kilometres are used to measure long distances a few centimetres long, but they are not so long that and the tree is a lot shorter than a kilometre. The unit in they need to use metres. between centimetres and kilometres is metres. 6. a) My math book is over 2 cm thick, my fingernail is B. I would use kilometres to describe the distance travelled. barely 1 mm thick and a pack of 100 sheets of paper is For example, if I use a map to find the distance, the scale less than 1 cm thick, so I’d use millimetres for b and c. on the map is in kilometres. C. I would use millimetres to describe the thickness. For 7. For example, a wire is pretty thin, not even 1 cm wide, example, if the bark is very thin, then it is probably less so using millimetres makes sense. than 1 cm thick, so it would make sense to use millimetres, 8. a) For example, thickness of a DVD or the diameter which is smaller than centimetres. of coins would be measured in millimetres. D. I would use millimetres to describe the thickness. b) For example, the length of a videotape or the diameter For example, a leaf is very thin, so it would make of a DVD would be measured in centimetres. sense to use millimetres, which is the smallest unit. c) For example, the length of an aisle or the height of E. For example, the length of a bug, the height of a new the store would be measured in metres. blade of grass, or the width of a small flower petal would d) Nothing in the store would be measured in kilometres be measured in millimetres. since a kilometre is too long. 1. For example, all the units include “metre” because they 9. No. For example, even the CN tower isn’t 1 km tall and are all metric units that describe part of a metre. it’s huge. 2. For example, the leaf was measured to the nearest 10. For example, there should be a unit for hundreds of millimetre because it was measured to the nearest tenth metres between decametre and kilometre. Centimetre is of a centimetre and a tenth of a centimetre is a millimetre. one hundredth of a metre and has an “i” like decimetre, 3. For example, different units are appropriate for different so the unit for hundreds of metres should be centametre measurements because some things are really big and if with an “a,” like decametre.

Assessment of Learning—What to Look for in Student Work… Assessment Strategy: investigation Application of Learning Key Assessment Question 8 • Ryan is in a video store. What items in the store, if any, might be measured in these units? a) millimetres b) centimetres c) metres d) kilometres (Score correct responses out of 4.)

Extra Practice and Extension At Home • You might assign any of the questions related to this lesson, • Have students discuss linear measurement with family which are cross-referenced in the chart below. members. They could ask for some examples of metric units of linear measure that are relevant to them, for example, the Mid-Chapter Review Student Book p. 149, Questions 1 & 2 distance from home to their workplace or to the home(s) of Skills Bank Student Book p. 156, Questions 1 & 2 relatives or friends, measured in kilometres; the dimensions of the home, rooms, yard, and so on, measured in metres; Chapter Review Student Book p. 160, Questions 1 & 2 the height, length, or width of pieces of furniture, measured Workbook p. 42, all questions in centimetres; and the dimensions of very small items, such Nelson Web Site Visit www.mathK8.nelson.com and follow as thumb tacks, measured in millimetres. the links to Nelson Mathematics 6, Chapter 5. Optional: Chapter 5 Mental Math p. 55 Math Background The internationally accepted system of metric units is called SI (Systeme International). In this system, there is one base unit for each aspect of measurement. For length, the SI unit is the metre. Other units are obtained by attaching Assessment: various prefixes to the metre. Kilo means a thousand, so Problem Solving/ 1 kilometre = 1000 metres; deca means ten, so 1 decametre = 10m; hecto means hundred, so 1 hectometre = 100m; Thinking Rubric, centi means a hundredth, so 1 centimetre = 0.01 m; and Masters Booklet p. 8 milli means a thousandth, so 1 millimetre = 0.001 m. In selecting an appropriate unit for linear measurement, students need to consider the context. In general, distances are measured in kilometres; things such as the size of their classroom are measured in metres; smaller items, such as small pieces of furniture are measured in centimetres; and very small items or dimensions, such as the thickness of a sheet of bristol board, are measured in millimetres. Optional: All measurements are approximations. The degree of Measuring Length Cards accuracy required varies in different situations. In some (Master) p. 62 contexts, great accuracy is required. For example, if the length of a pencil is 12.4 cm, its length had been measured to the nearest millimetre or tenth of a centimetre.