Addition and Subtraction with Ten Unit of Study: Addition and Subtraction Strategies to 20 Global Concept Guide: 3 of 5

Content Development  This unit focuses on students being able to fluently add and subtract numbers to 10 and having experiences adding and subtracting within 20.  While we teach each of the strategies, it is important to provide daily opportunities for students to apply the strategies within problem solving scenarios (word problems).  The ability to decompose a number to add and subtract will be necessary as students begin to add and subtract larger numbers.  Several learning tasks have been embedded that are from the Dana Center. These researched literature based tasks correlate with the lessons in Go Math and are engaging and user friendly.

Day 1 and 2  Engage students by having them list ways to make ten. Then pose the problem Have students explain how they knew the answer so quickly. Discuss how adding a ten comes quickly to us and we can use that as a strategy.  Start with one addend being 8 or 9 to show how we can easily make a ten. As students begin to understand the addends can become slightly smaller.  Use ten frames to show both addends and how a ten can be composed by shifting part of an addend to the other. Verbalizing the actions taking place will build understanding within the students. 9+4= 10+3=13

Day 3  Making a ten to subtract on Day 3 may be difficult if students do not have a conceptual understanding of decomposing and making a ten to add. This is critical in order for students to be successful.  Facilitate discussion about the relationship between addition and subtraction.  Students may need additional practice with decomposing numbers in different ways.  Informally assess students by the end of Day 3 so that differentiation can be planned based on needs for Day 4.

Day 4  Based on students needs, use Day 4 to continue modeling, problem solving and explaining the use of the strategy of making a ten to add.  If students are struggling with making a ten, use selective parts of the following task to differentiate. Making TensMaking Tens  If students are able to make a ten, but struggle with knowing what else to add, encourage the use of manipulatives to model the problem and actions taking place.  Use HOT question # 3 to challenge students that have a strong understanding of this strategy.

Enrich/Reteach/Intervention  Enrich  Students work through problem solving scenarios and apply strategies  Students work through more complex problems and find was to make a ten.  Intervention/Small Group  Work with students on building tens and identifying number pairs for tens, as well as other numbers from 0-10.