Building Blocks

In this activity, students will demonstrate their ability to use a variety of strategies to mentally solve addition problems. Understanding the way these strategies work helps build students’ number sense, flexibility with numbers, and confidence in manipulating numbers in a variety of ways. Students will learn, review, and practice using four addition strategies before showing their strategy skills on a mini quiz.

### Objectives:

Students will be able to use a variety of number-sense based strategies to mentally solve addition problems.

Students will use writing to reflect on the effectiveness and efficiency of each strategy used.

### Materials:

• Building Blocks of Math series, specifically Addition

• Addition Strategy Spotlights PowerPoint Presentation

• Addition Strategy Spotlights Note-Taking Guide (1 per student)

• Optional Assessment: Addition Strategy Spotlights Mini Quiz (1 per student)

• Optional: Manipulatives (counters, beads, tokens, etc.)

• Optional: Blank tens frames

### Differentiation Considerations:

For additional support, allow students to use manipulatives and/or blank tens frames to help make the addition strategies more concrete and therefore easier to understand. Students can physically move manipulatives to make tens, find friendly numbers, or double their amounts.

• Finding Tens

• Friendly Numbers

• Doubles

• Near Doubles

### Procedures:

These procedures are general and can be applied to each strategy spotlighted in this activity.

1. Name and describe the strategy using the slides in the presentation.
2. Review/model your thinking aloud for both examples, highlighting the strategy and allowing time for students to process and ask relevant questions.
3. Transition and provide one note-taking guide to each student. Present the first problem and provide them 1-2 minutes for students to think independently and solve the problem in their guide. Next, have students spend another 1-2 minutes sharing their strategy choice and thinking with a neighbor. Finally, allow 2-3 students to share their thinking with the entire class. If possible, determine students to share ahead of time. It can be beneficial to highlight strong uses of a strategy or to address any major misconceptions here. Repeat these steps with the remaining problems on the note-taking guide.
4. Read the written response question aloud and provide 3-5 minutes for students to reflect and respond independently. Provide time for 2-3 students to share their thinking and encourage students to add anything interesting from their peers to their own written responses.
5. Summarize the activity by reviewing the strategy and readdressing any major misconceptions.
6. Repeat steps 1-5 for each strategy. Consider highlighting one strategy at a time (per class period, per week, etc.) and practicing related problems so students have time to practice and develop their strategic thinking.

Optional: After students have had exposure to and practice using all four strategies highlighted in this activity, consider using the optional mini quiz as a form of assessment. Here, students are provided four addition problems and asked to solve them using whatever strategies they would like. In addition, students must justify why they chose the strategies they did.