SWBAT solve 2 part story problems with two different actions (+ and -).

Build investment in solving story problems with this lesson where students are working in Santa's workshop. *Elf image and movie, copyright MMIII New Line Productions, Inc.*

5 minutes

This lesson really stretches kids' thinking on the critical 1.OA.1 standard. Students have been working on solving story problems for this entire unit. Now they get a push to try solving problems that involve 2 steps!

This extension allows kids to think deeply about how to make sense of a problem and then persevere in solving it (MP1). They have to think about exactly what they know at each stage of solving the problem and then use what the first part of the problem told them to help them solve Step 2!

**Review:**

We have been working on two part story problems where two different actions happen. With the Grinch, we saw that at first he stole the presents, but then he brought them back.

**Connect:**

In real life, we have to solve multiple problems at a time, we don't just focus on one action. Often one action happens and then it is followed right away by another action.

**Objective:**

How can I solve a 2 part story problem that has two different actions?

See attached reflection for how I built in a little motivation during the slow march to winter break!

15 minutes

This lesson pushes students to understand how to work through a 2 part problem, which aligns to Mathematical Practice 1, making sense of and persevering in solving problems.

**Sticky key point to reiterate throughout the lesson: These problems are connected! It's one big story where 2 things happen. **

I have a story problem here for you. Two things happen in this problem, but I separated it so we would have space to work it out.

**Present problem: The elves made 5 presents on Monday and 5 presents on Tuesday. How many presents did the elves make? **

- Partner talk: Show your partner how many presents they made and prove your answer.

Now keep that part of the story in your brain while I read the next sentence.

**Next, Santa put 3 of the presents in his sleigh. How many presents do the elves have now? **

I'll have students act out the story by choosing an "elf" and giving a Santa hat to one child to be "Santa".

**Guiding Questions:**

- How many toys did the elves have before Santa took some?
- What number sentence would we write for the second part of the problem? Why would we start with 10?
- How many presents do the elves have at the very end of the story? Let's retell everything that happened.

To help students see the connection, I'll draw an arrow from the first part of the problem to the second part.

15 minutes

I'll have students read the problems on the rug before going to their desk, reiterating that the two parts of the story problem are connected.

**Group A: Intervention**

Students receive numbers under 10. This group may have students who are usually very proficient with 1OA1 (Solving story problems with numbers under 20) but need smaller numbers to help them act out this problem. In this case, students are actually focusing on MP1, Make sense of and persevere in solving problems.

**Group B: Right on Track**

Students solve problems with numbers under 20

**Group C: Extension **

Students solve problems with numbers under 50

*See attached videos (Part 1: Group C Strategy and Part 2: Group C) of a student solving a Group C problem. Watch how he attempts to use at 10s and has to struggle a little bit to figure out how to use them! In Part 2, you'll see how we acted the second part of the problem. *

Independent practice pdf is attached! I left the numbers out so you can write numbers in that are most appropriate for your students!

15 minutes

We will come back together and work through a Group B problem, sharing one student's strategy for solving. We will focus on the actions of the problem so students are still thinking about how to work through a problem with 2 parts.

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