Applying Addition and Subtraction Strategies with 3-digit Numbers

Unit of Study 6: 3-digit Addition and SubtractionGlobal 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.

Day 2Essential 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. By the end of Day 2, students will be able to solve multistep problems

involving 3-digit numbers. Possible daily journal questions.

Day 3Essential 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 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.

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 Animated math model ~ Three digit subtraction regroup hundreds

Enrich Enrich TE p. 313B Enrich book ~ E64 Enrich TE p. 317B