Decompose Two- Dimensional Shapes Unit of Study: Two-Dimensional Geometry Global Concept Guide: 3 of 4

Content Development  Pattern blocks are excellent tools for students to use as they analyze composite shapes. Students can place the pattern block directly on the composite shape and turn it, flip it, or slide it to fit inside the composite shape.  Students may first try to fit every pattern block within a composite shape. As they become more familiar with the relationships, children will choose specific pattern blocks to develop their answer.

Day 1  Day one is an introduction to the concept of decomposing shapes. Go Math Lesson 12.6 provides simple tasks that encourage students to explore with pattern blocks.  Students need ample opportunity to manipulate pattern blocks directly on top of the composite shapes they are decomposing.  Students may become frustrated at first, try encouraging them to be “shape detectives”. At first, trial and error will be their only method, but they will soon develop strategies and these should be highlighted when sharing solutions.

Day 2  Excursions lesson: I Spy Shapes is a good introduction to tangrams.I Spy Shapes  Tangram Puzzles encourage students to try numerous strategies for decomposing composite shapes  Tangram puzzles provide a quick opportunity for tiered differentiation: try giving more complex puzzles to those students ready for enrichment, while allowing students requiring intervention to work on simple composite shapes  The Super Source Books also provide many ideas for different Tangram pattern puzzle  You may want students to glue the puzzles into their journals to keep as a record

Day 3  ETA SuperSource lesson: Secret Builder is a cooperative task. Students are asked to choose a specific number of tangrams and they must create a “Secret” object. They must create clues so their partner can attempt to create their secret object.Secret Builder  As the day’s Engage you may want to model the task by having a secret object prepared beforehand. Give sample clues and allow the class to guess your secret object using their tangrams.  Students can be paired strategically to provide differentiation. You may want to challenge some groups by giving them extra tangram pieces or by adjusting the rules.

Day 4  Possible Engage: Problem 11 on Go Math p Many students will see only 4 squares, look for students that see the 5 th large square to share their thinking.  Go Math Lesson 12.7 focuses on pictorial representations of decomposing shapes.  Day 4 should give you the opportunity to pull small groups as necessary for remediation. By this point, students should be able to work independently or in small groups to complete their tasks.

Enrich/Reteach/Intervention Enrich: Give students increasingly challenging Tangram Puzzles Challenge students to create more than one (or two) way to decompose a puzzle and record solutions in their journal Intervention/Small Group: Provide students with less challenging tangram puzzles Reteach 12.6 (p. R96) Tier 2 small group intervention activity (TE p. 505B) Tier 2 small group intervention activity (TE p. 509B)

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