Step One, Step Two

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Objective

The students will be able to solve two-step "real world" problems by using the answer to the first step of the problem to help them answer the second step.

Big Idea

The big idea of this lesson is that sometimes it may be necessary to answer one problem to help answer another problem.

Activator and Materials

10 minutes

To begin the lesson the students turn and talk about what they know about using addition and subtraction to solve word problems.  If necessary, guide the students to think about how they can use addition to solve addition sentences, and that they could use subtraction to solve "take away" and comparison word problems.  It may be helpful to have the students think of a word problem for each one of the different kinds of word problems.  

My students have had a great deal of practice with word problems because they complete daily "Mystery Math." More practice or discussion may be necessary for those students who haven't had as much practice with it.

Develop the Concept

20 minutes

I have the students move to our rug area and sit in a circle for the next step of this lesson.  I find that it is most helpful for the students to become actively involved in this lesson in order for them to really understand how to solve problems with two steps.  

Choose a student to become the "trick-or-treater" in the problem. Read aloud the following problem. As you read the problem, have the student act out what is happening in the problem.  We used tennis balls to represent the candy.

"A trick-or-treater gets 10 pieces of candy in their bucket.  While they are walking they accidentally drop 5 pieces of candy.  How many pieces of candy does the trick-or-treater have now?"

Two Step Word problem - 1

As you are reading the problem, stop at each step and ask the students to direct the "trick-or-treater."  When you are finished, ask the students to see if they can determine which mathematical operation they should use to solve the problem.  Write the number sentence on the board and continue on to read the next step of the problem.  Continue to have the "trick-or-treater" act out what the problem says, under the direction of the class.

"Once the trick-or-treater gets home, s/he eats 4 pieces of his/her candy.  How many pieces of candy does the trick-or-treater have left?"

Two Step Word Problem - 2

Discuss with the students which mathematical operation they should use and what number sentence they should write (5 - 4).  Ask the students to turn and talk about why they chose the 5 as the subtrahend and why the 4 is the minuend, as you only see one of those numbers in the word problem.  They should understand that they had to use the answer from the first word problem in order to solve the second problem.

It may be helpful to have the children act out a few more problems.  As you teach the lesson, assess the students' understanding and adjust the amount of practice they get accordingly. 

Two Step Word Problem - 3

Practice the Concept

20 minutes

Once you feel students have grasped the idea of a two-step word problem, have students work independently to complete the One Step, Two Step Practice. It is important to continue to practice the idea of solving two step word problems while it is fresh in their minds.  When students finish, they work in partners to create a word problem of their own that could be "acted out" for the class to solve.

Summarizer

10 minutes

In a lesson where a more complex idea has been taught, it is critical to make sure there is adequate time to  come back together as a class, preferably in the meeting/rug area, again in a circle.

Here students share the word problems that they created in partners, challenging other students to volunteer to act out the problem they created.  Students who were unable to get to the final step can participate by using a practice problem, and with the assistance of their peers and teacher, come up with a simple scenario. With every problem, it is important for the class to discuss the mathematical operations necessary to complete the word problem's two steps.