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**Early algebra, investigating linear functions, series 5 of 7,ladder problem, Clip 3 of 7: Recording the procedures for ladders with odd and even numbers of steps [video]. ** Retrieved from

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TitleEarly algebra, investigating linear functions, series 5 of 7,ladder problem, Clip 3 of 7: Recording the procedures for ladders with odd and even numbers of steps

PublisherNew Brunswick, N.J.: Robert B. Davis Institute for Learning, , c2005-12-15

DescriptionIn the third of seven clips from an after-school enrichment session in an urban middle school, two 7th grade boys, Ariel and James, are exploring ideas about linear functions. When Ariel explains his reasoning, researcher John Francisco asks him to write out the "rules" that he has developed for solving the ladder problem. Ariel has one procedure for a ladder with an odd number of steps, and a second procedure for a ladder with an even number of steps. Ariel writes out his odd and even rules, demonstrating each procedure with an example which he sketches on his paper. He proposes a ladder with nine steps to illustrate his procedure for an odd number of steps and a ladder with six steps for an even number. James appears to be recording his method as well. Researcher Prashant Baldev is observing. This clip is featured in Clip 3 of Series 7: Early algebra, investigating linear functions, Ariel's 8th grade interview, revisiting the IML Ladder problem.

The worksheet wording for the Ladder Problem:

A company makes ladders of different heights, from very short ones to very tall ones. The shortest ladder has only one rung, and looks like this (we could build a model of it with 5 light green Cuisenaire rods.) A two-rung ladder could be modeled using 8 light green rods, and looks like this. Build a rod model to represent a 3-rung ladder.

How many rods did you use? How could you represent the number of rods needed if you were to build a ladder with any number of rungs?

The questions as posed to Ariel and James:

Explain how you would predict the number of rods needed for a ladder with a particular number of steps?

Write down your procedures for each case - a ladder with an odd number of steps and also a ladder with an even number of steps.

RightsThe video is protected by copyright. It is available for reviewing and use within the Video Mosaic Collaborative (VMC) portal. Please contact the Robert B. Davis Institute for Learning (RBDIL) for further information about the use of this video.

Date Captured2005-12-15

Local IdentifierB17B18-ALG-VAR-CLIP003

Related Publication

__Type__: Related publication

__Label__: Ed.D. dissertation references the video footage that includes Early algebra, investigating linear functions, series 5 of 7, ladder problem, Clip 3 of 7: Recording the procedures for ladders with odd and even numbers of steps

__Date__: 2009

__Author__: Baldev, Prashant V. (Rutgers, the State University of New Jersey)

__Name__: Urban, seventh-grade students building early algebra ideas in an informal after school program

__Reference__: QA.B175 2009

Source

__Title__: B17, Early algebra, investigating linear functions, Series 5 of 7, Ladder problem (student view), Grade 7, December 15, 2005, raw footage

__Identifier__: 17-20051215-PFLD-SV-IFML-GR7-ALG-VAR-RAW

Source

__Title__: B18, Early algebra, investigating linear functions, Series 5 of 7, Ladder problem (student view), Grade 7, December 15, 2005, raw footage

__Identifier__: B18-20051215-PFLD-SV-IFML-GR7-ALG-VAR-RAW