Understanding Centimeters and Meters Unit of Study: Length in Metric Measure Global Concept Guide: __1_ of __3_

Content Development  A common misconception students have when measuring is that they overgeneralize the numbers on the ruler. In the example below the child might say that they crayon is 11cm in length. Lining up cm cubes next to the crayon will reinforce the idea that the ruler is a representation of the units to be counted.  “Measurement reasoning involves unit-length iteration, that is, determining the number of fixed unit lengths that fit end-to-end along the object, with no gaps or overlaps.” (Battista, 2007 p. 894)

Day 1  The focus of day 1 is have students build a concrete understanding of a centimeter by using centimeter cubes to measure the length of objects.  There are lesson components in GoMath Lesson 9.1 that are listed in the lesson ideas on the GCG to pull from for this day.  Students should be allowed to use the unit cubes to measure objects around the classroom and record their results in centimeters on the “Measurement Record Chart” listed in the lesson ideas.  Students need to practice measuring items on paper as well but it is essential to expose them to real life measuring opportunities first.

Day 2  The focus of day 2 is for students to use a centimeter ruler to measure the lengths of objects.  There are lesson components in GoMath Lesson 9.3 that are listed in the lesson ideas on the GCG to pull from for this day.  Students should be encouraged to use a centimeter ruler to measure objects around the classroom and record their results in centimeters on the “Centimeter Record Chart” listed in the lesson ideas.  Students need to practice measuring items on paper as well but it is essential to expose them to real life measuring opportunities first.

Day 3  The focus of day 3 is to build students understanding of measuring in meters and how it relates to centimeters.  There are lesson components in GoMath Lesson 9.5 that are listed in the lesson ideas on the GCG to pull from for this day.  The lesson should build students understanding that 100 centimeter is equal to 1 meter. Exposing them to concrete activities like the engage activity on T.E. p 449 will help them make this connection.

Day 4  The focus of day 4 is for students to better understand which is the more appropriate tool (centimeter ruler or meter stick) to use when measuring the length of an object.  Students need to be exposed to several opportunities to determine what the appropriate tool would be.  For example: Would it make more sense to use a centimeters or meters to measure the length of a textbook? Students should select centimeter because it is going to give a more accurate measurement and 1 meter is larger than the length of the textbook.  Students could be given specific objects to measure in the classroom and it would be their job to determine the appropriate unit of measurement to measure the object. They should justify their reasoning. You could use the “Appropriate Measurement” sheet listed under lesson ideas. Note: you may need to change the listed objects to fit your classroom

Enrich/Reteach/Intervention  Enriching Activities-Enrich T.E. p 433B and Enrich T.E. p 441B are both great hands on ways to stretch your students thinking. A little prep work needs to be done before having students do this activity.  Reteach Activities-Use the Reteach pages R86, R88, and R90 to reteach. There are limited practice problems so you could use them as a guide to create additional opportunities to remediate students in need.  Students may need to use the centimeter cubes for additional days to really make the concrete connection between unit cubes and centimeters and meters.

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