SWBAT find combinations of 10 and record them using number sentences.
SWBAT articulate what strategy they used to find the combinations.

The majority of the Common Core for first graders is built around the concept of base 10. Students build their understanding of 10 in this rigorous task!

5 minutes

Common Core emphasizes instruction through complex tasks. In this lesson, students have to think critically about ways to make a single number, which is very rigorous for a little one! The more students understand what 10 means and how to build it, the better they will understand future Operations and Algebraic thinking standards, as well as the Numbers in Base 10 standards.

**Review:**

We have been learning about the combinations of 7, 8, 9 and 10. Today we are going to push our brains to learn all the ways to make 10.

**Connect:**

10 is our best friend in math! When we understand all the ways to make 10, it will help us as we solve hard problems in first and even 2nd grade!

**Objective:**

Your thinking job is: What strategies can I use to find the ways to make 10?

15 minutes

Present the problem on anchor chart:

I want to build a magic wand out of 10 cubes. Some of my cubes are black and some of my cubes are yellow. How can I build my magic wand?

To push kids to think about the missing part, I'll present them with 6 black cubes I already have and ask them to help me finish building my wand.

Guiding Questions:

- How many cubes long will my magic wand be in total?
- How many cubes are black?
- What am I trying to figure out?
- Partner talk: How many yellow cubes will I need to use to make my magic wand?

**See this video for the rest of the opening discussion! You'll see how we discuss the missing part and how we find other combinations as a class.**

15 minutes

I'll give students 5-7 minutes to figure out the missing part and record how they figured it out in their math journals. If students finish early, they can show other combinations they found in their journal.

We will then briefly come back together to discuss what combinations they found.

*See this video of our class strategy share!* In the video, you'll see how we quickly discuss 2 strategies for finding the missing part-cubes and counting on- before I send kids off to find other combinations on their own.

15 minutes

**Group A: Intervention**

Students have the support of ten boxes to place the cubes in. Students record combinations.

**Group B/C: On Track and Extension**

Students use a variety of strategies to find all of the combinations of 10. If students finish, they write about how they know for sure they have all of the combinations.

10 minutes

We will come back together and chart all the ways we found to make 10! I'll chart them in "order" from 0+10, 1+9, 2+8...all the way to 10+0.

*See attached image for example of the chart we made.*