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XY Encounter

Funded by the US Department of Education

Teacher's Guide: Part 4: Introduction - "I've got your number."

Watch Video Clips @ XY Encounter Streaming Video Page

Map of Teacher's Guide	Part 1	Part 2	Part 3	Part 4
	Introduction	Introduction	Introduction	Introduction
	Pause Point 1	Pause Point 1	Pause Point 1	Pause Point 1
	Pause Point 2	Conclusion	Pause Point 2	Conclusion
	Pause Point 3		Conclusion
	Conclusion

Setting:

Our dynamic duo is getting closer! It’s now after school and Max and Keisha are separately pondering the most recent clues, each approaching the problem in his or her own unique way. Max concludes from the symbols that the alien is leaving. Keisha is convinced all clues lead to 3 1/2, but doesn’t know how to put it all together. Max, whose watch loses time, uses the visual clue of a clock to realize the message means the alien is leaving at 3:30! Keisha, reciting ideas out loud, refers to objects in her bedroom to stumble upon a possible solution. Suddenly her eyes fall on the bedroom clock and she realizes that the alien has given them a signal for time in the only way it knows how to communicate. Separately, Keisha & Max have solved the problem and they breathlessly race to the cave…

Standards:

• Develop meaning for fractions as parts of a unit whole, as part of a collection, as numbers and as a division of whole numbers.
• Develop strategies for judging the size of fractions and decimals and for comparing them using a variety of models and of benchmarks (such as 1/2 or .5).
• Understand and demonstrate congruence.

Objectives:

• Students interpret multiple representations to name equivalent fractions.
• Students represent fractions and mixed numbers using physical models.

Materials:

Prepare student copies of the activity sheet, “I’ve Got Your Number” (.pdf file) and an overhead transparency, if desired.
Download PDF Activity Sheet | Get Acrobat
A Printable version of this activity sheet is available in PDF format.
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You can find out if you need it by clicking on the PDF link.

Students will need scissors to cut teardrop shapes from the worksheet. You may also wish to use geoboards.

Note: You might want to view the Elementary School Mathline Project video, “To Half, or Half Not” for ideas (www.pbs.org/mathline/).

Mathematically Speaking:

Students are already familiar with halves and creating halves by cutting objects. Typically a straight line cut is used for halving something. Students have less experience with irregular cuts. Note that Keisha showed how to test the shapes by placing one piece over the other and inspecting them to determine they are the same size and shape. Since the figures are congruent and two make a whole, each is 1/2. It is often difficult for students to judge whether irregular shapes are equivalent.

Background Information:

Equivalent fractions are the focus in this episode. Multiple representations include whole numbers with a proper fraction, a whole number with a decimal, and geometric representations.

Vocabulary:

The XY Encounter, Part 4 video lays the groundwork for introducing: