Applying Addition and Subtraction Strategies with 3-digit Numbers Unit of Study 6: 3-digit Addition and Subtraction Global Concept Guide: 4 of 4

Content Development  These three days should be focused on the SMP 4 of Modeling with Mathematics. The teachers should work together to find real and relevant problems for students to solve involving adding and subtracting 3-digit numbers.  While the title of this GCG says the traditional algorithm, students SHOULD NOT be required to only use this strategy.  3 days were given to this GCG to allow you to pull small groups and remediate or enrich students based on their needs.

Day 1  Essential question: How can I use a variety of strategies to solve real- world problems?  Problems similar to those in lesson 6.6 should be used to guide today’s lesson or Enrich page E61.  Students should be encouraged by you to use a variety of strategies to solve a given problem and then be given the opportunity to discuss the efficiency of the strategies they used.  By the end of Day 1, students will be able to use a variety of strategies to solve real-world problems. Possible daily journal questions.daily journal questions

Day 2  Essential question: How can I solve multistep problems involving 3-digit numbers?  Sample engage question:  Mario had $128 and Luigi had $174. They combined their money to buy a Xbox. If the Xbox costs $400, how much more money do they need?  Have students act out or model what is happening in the story.  Questions you could ask: ?What would a reasonable answer be? ?Does your solution make sense? ?Explain how you got your answer? ?What is another way to solve this problem? ?Explain how you know your answer is correct?  Additional problems you could use. Additional problems  By the end of Day 2, students will be able to solve multistep problems involving 3-digit numbers. Possible daily journal questions.daily journal questions.

Day 3  Essential question: How can I check my answer to see if it is correct?  Students should know to check subtraction using addition. They should also be able to check addition with multiple strategies.  Sample engage question:  Sean was having a wonderful time riding the rides at Disney World. He waited in line for 346 minutes at It’s a Small World. He waited for 289 minutes at Space Mountain. How much longer did he wait at It’s a Small World than Space Mountain? Solve and find a way to check your solution.  Students should solve and find a way to check their solution. Inverse operation and efficient strategies should be highlighted for all students to see. Additional problems Additional problems for students to solve or E63.  By the end of Day 3, students will be able to check their work to see if there answer is correct. Possible daily journal questions.daily journal questions

Enrich/Reteach Reteach  Students may still need models to support their understanding.  If students are struggling with multistep, you may want to replace the numbers with single digit numbers to focus on the actions in the story and then replace with the 3-digit numbers.  Reteach book R61, R62  Animated math model ~ Addition with regrouping up to 3-digits~ Addition with regrouping up to 3-digits  Animated math model ~ Three digit subtraction regroup hundredsThree digit subtraction regroup hundreds Enrich  Enrich TE p. 313B  Enrich book ~ E64  Enrich TE p. 317B