##
* *Reflection: Checks for Understanding
Where is the Question - Section 2: Teaching the Lesson

We concentrated today on finding the words in word problems that help us to know whether to add or subtract. The students did a great job finding the words, and were able to determine if they needed to add or subtract.

But, then they were not careful with the computation. One group gave 55 as the answer for 85 - 35. When questioned, they said they took 3 away from 8 to get 5. (I asked if this was tens or ones and they said tens.) Here students were not attending to the precision of solving the problem (MP6)

Then they told me they subtracted 5 from 5 and got 0, but they wrote 55. When I pointed this out they had trouble seeing why the 55 was different from what they told me.

I saw similar mistakes with other partnerships. I think I need to teach students about checking their work to see if it makes sense.

I realized that determining the operation was taking a lot of the “brain” focus in this activity. Also numerical sense making is not yet in place. Although one of my goals is for students to make sense of the problem (MP1), and persevere in solving it, I realized that students had trouble maintaining the focus and stamina to do both. When the focus is only on manipulating numbers, they are in the “groove”, but now like are being asked to juggle two things - determining operation and manipulate numbers. It will take additional practice for them to be able to maintain the focus throughout a 2 part problem such as these.

*FInding the Words, Forgetting the Math*

*Checks for Understanding: FInding the Words, Forgetting the Math*

# Where is the Question

Lesson 1 of 12

## Objective: SWBAT identify the problem and operation within a word problem.

## Big Idea: Students can perform addition and subtraction within 100 using a variety of math tools, however, determining which operation to use is a higher level thinking skill that is being introduced in this lesson.

*65 minutes*

#### Warm Up

*15 min*

We warm up with several *partners of 100* addition and subtraction problems to solve mentally (2NBT.B8).

I ask, *"How much is 40 + 60?"* They record the answer in their math journal.

I follow with 100 – 70, 80 + ? = 100, 100 – 10 = , and 50 + ? = 100.

With each problem students share their solutions to the problems, telling not only the answer but also the way they found the answer.

Next, I ask them some *plus and minus 10* problems within 100.

I ask, *"How much would 85 + 10 be? What would 76 – 10 equal?"* I finish with 63 +10 = ? and 92 – 10 = ?.

I ask the students, *"How did you know what to do with the numbers in each problem?"* (The +/- signs.)

I tell them that the +/- are like road signs. *A stop sign tells us to stop our car. The +/- signs tell us what to do with the numbers in a math problem.*

I put the following on the board: 60 + 40 = 100

Underneath, I write: 60 – 40 = 20.

*Why did 2 problems with the same numbers have different answers?* The +/- signs tell us what to do.

*Today we are going to see what to do when the road signs aren’t so clear.*

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#### Teaching the Lesson

*20 min*

I invite students to come to the rug area. On the white board (easel, overhead or poster) I put the + symbol over one column and the - symbol over the other column. I tell students that today we will look for words that help us to figure out which *road sign* to use. I want students to attend to the structure of a word problem and find the words that would best help them to solve the problem. (MP7)

I post this problem at the bottom of the white board.

*I read 63 pages of my book on Monday. On Tuesday I read 10 more. How many pages have I read altogether?*

I ask students if there are any words in the problems that could act as street signs?

Responses can include *how many,* *altogether* as addition road signs). I ask if anyone can come and write the number sentence for the problem on the board? (63 + 10 = 73). I put the words *how many,* *altogether* in the + column.

Next, I post this problem:

*I started with 48 cards. I gave 20 to a friend. How many are left?*

Again, I ask which words might be the *street sign*? (How many left?) I ask if anyone can come up and write the number sentence for this problem? (48 – 20 = 28). I put the words *how many left* in the – column.

I post one more problem on the board:

*I build a tower with 35 blocks. My friend builds a tower with 25 blocks. How many more do I have? *

I ask if anyone can come up and write the number sentence? (35 – 25 = 10 or, they may write 25 + ? = 35.) If they write the first choice, I put the words *how many more* under subtraction. If they give the second choice, I ask how might we solve the problem? We can count up from 25 to 35, or count down from 35 to 25. This is a comparison problem. We don’t want to add the two numbers, so we put the words *how many more* in the subtraction column.

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#### Independent Practice

*15 min*

I tell students that today they will work with a partner to solve some word problems. worksheet - where is question.docx They will look for the words that help them know what to do (the *street signs*) and record these words at the top of their papers so that we can put them all together to make a class chart of math *street sign* words.

I partner students heterogeneously so that they can help one another find the math *street sign* words.

I give students directions and then circulate around the room to support students who may be struggling.Finding the Words

Common Core Standard 2NBT. B 5 says “Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.” My goal is for students to increase their understanding of the properties of operations and the relationship between addition and subtraction as they solve problems today.

I also expect them to be able to explain why the addition and subtraction strategies they have chosen work to solve the problem (2NBT. B 9). Explaining The Solution

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#### Closing

*15 min*

I repost the chart I started with at the beginning of the lesson and ask for any other words that students may have found in the word problems that helped them know which street sign (+-) that they should use to solve a given problem. We post the chart in the classroom for students to refer to later.

*expand content*

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- UNIT 1: What and Where is Math?
- UNIT 2: Adding and Subtracting the Basics
- UNIT 3: Sensible Numbers
- UNIT 4: Sensible Numbers
- UNIT 5: Everything In Its Place
- UNIT 6: Everything in Its Place
- UNIT 7: Place Value
- UNIT 8: Numbers Have Patterns
- UNIT 9: Fractions
- UNIT 10: Money
- UNIT 11: The Numbers Are Getting Bigger
- UNIT 12: More Complex Numbers and Operations
- UNIT 13: Area, Perimeter and More Measurement
- UNIT 14: Length
- UNIT 15: Geometry
- UNIT 16: Getting Ready to Multiply
- UNIT 17: Getting Better at Addition and Subtraction
- UNIT 18: Strategies That Work

- LESSON 1: Where is the Question
- LESSON 2: Playing Teacher - Checking Our Work
- LESSON 3: Estimation - an introduction
- LESSON 4: Using Models to Add and Subtract
- LESSON 5: Comparing Temperatures a Science and Math Exploration Part I
- LESSON 6: Comparing Temperatures A Math and Science Comparison Part II
- LESSON 7: Checking Subtraction
- LESSON 8: Introducing the Addition Algorithm
- LESSON 9: Addition Algorithm Rote or Understanding
- LESSON 10: Adding Repetitive Sets of Numbers
- LESSON 11: Adding and Subtracting in Columns
- LESSON 12: Getting Better At Addition and Subtraction Final Project