##
* *Reflection: Checks for Understanding
SMALL, SMALL, BIG - Section 3: Independent Practice

As students started the independent practice I was pleased with how well they were taking the numbers, placing them in the large or small boxes, writing and solving an equation. Yeah! Lesson learned.. almost! Suddenly the students came to a problem that presented the smaller number, then the larger number and then a subtraction sign.

Order is everything. Too many of the students did not stop to think before writing the equation. They placed the two numbers incorrectly in the large and small boxes and then tried taking the larger number away from the smaller number. Several of them raised their hands and said that it wouldn't work. Several of them just flipped the numbers and ended up with an answer that did not match the problem.

What I had thought of as understanding of the concept of larger and smaller numbers and how they work in addition and subtraction problems was more an understanding that you take the first number, subtract the second and get an answer. Had I not presented the numbers in this order, I would have assumed understanding of the concept of how addition and subtraction work.

By checking for understanding, I know I need to reteach this concept and reinforce the understanding of the concept of subtraction.

*Order is Everything*

*Checks for Understanding: Order is Everything*

# SMALL, SMALL, BIG

Lesson 10 of 15

## Objective: SWBAT connect part-part-whole relationships to fact families to solve for a missing number.

## Big Idea: All things are made up of parts and wholes, even math equations. Can you find the parts and wholes of number sentences, even if they are hidden?

*50 minutes*

#### Warm Up

*10 min*

Today I start by reviewing fact families with students. I present 2 equations from the same fact family. I write them on the board with ? for the missing numbers:

19 - ? = 11

11+ ? = 19.

I ask students to solve the two sentences in their math journals. I ask students if they notice anything about the 2 number sentences.

We discuss their observations. I am hoping that students will realize that the equations are from the same fact family and that solving one will give them the answer to the second. (This is a review of work earlier in the year, but now with larger numbers.)

I put up the following equations: ? + 35 = 60 and 60 - ? = 35. I ask students again to solve the problems and then we discuss what they have found.

I tell students that today we will work with fact families for larger numbers as we look for parts and totals in numbers.

*expand content*

#### The Game

*20 min*

I bring students to the rug to play a new game. I model the game first with one child as my partner. The other children sit on the edges of the rug to observe how the game is played.

I put out a board that has a square on it. The square is divided horizontally. The top half is labeled as the Total. The bottom half is further divided vertically into two smaller pieces which are each labeled as Parts. I ask students if they remember seeing the chart yesterday? Ok today we are going to play the game with these boards.

I will start, I draw 4 cards (cards from a regular card deck, using only the numbers 1 - 9). I use the cards to build 2 numbers. Then I roll a sign die (+ or - marked on all 6 sides). The roll tells me if I am going to add my two numbers, or subtract one from another. If I am going to add, I place the two numbers in my two Part boxes because students know that when they add they get a bigger number so the bigger space should be empty. If I am going to subtract I place the larger number in the Total box and the smaller number in one of the Part boxes because subtraction gives me an answer smaller than what I started with (unless the other number is zero) so I need to leave a smaller space empty. I write a number sentence for my numbers and sign on my white board. Now I use the calculator to find the answer. My partner must use another strategy from his/her suitcase to solve the problem. If my partner gets the correct answer, he/she gets one point. If he/she is incorrect no point is given and we switch roles. The game allows children to model with mathematics to help them understand the operation they need to perform and what they are aiming for (larger or smaller number) (MP4).

I have my partner walk through the steps this time.

I check for understanding from all the students. (Thumbs up if you could play the game, thumbs down if you are still not sure what is going on). When students are ready, I partner them up to play the game. I circulate around to check on how students are doing.

*expand content*

#### Independent Practice

*15 min*

At this point all students have had a chance to play the game and to experiment with solving equations using the idea of Big, Small, Small parts. I now want them to explore using this strategy of their own.

Because there are diverse levels in the room, I have 2 different papers ready for students. One uses larger numbers than the other. These problems present 2 numbers and a sign. Students write the equations from the Big, Small, Small boxes and then record the strategy they are using to solve the problem. Children should be making use of the structure of the Big, Small, Small boxes to help them solve the equations. (MP7)

I circulate around the room to check in with individual students. If I see several students who are all still having trouble with moving the numbers to the graphic organizer and then into an equation, I will take them as a small group and work with them to be successful with the work.

*expand content*

#### Closing

*5 min*

Students respond to a sentence starter in their journals to help me assess their understanding of the reasons for using a variety of strategies to solve mathematical equations.

Sentence starter: When I choose a math strategy to solve a problem I think about ___________

or: I know how to pick a strategy to solve a math problem because ___________________

*expand content*

##### Similar Lessons

###### Cover Up

*Favorites(6)*

*Resources(17)*

Environment: Suburban

###### Domino Addition: Understanding the Part/Part/Whole Relationship

*Favorites(26)*

*Resources(20)*

Environment: Rural

###### It's As Basic As That

*Favorites(17)*

*Resources(11)*

Environment: Suburban

- 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: Adding Three or More Numbers
- LESSON 2: Houses of Addition
- LESSON 3: Comparing the Weather
- LESSON 4: Balancing and Comparing Data
- LESSON 5: Subtraction Houses
- LESSON 6: Subtraction Houses Part 2
- LESSON 7: Time to Practice
- LESSON 8: A Suitcase of Math Strategies
- LESSON 9: What Do I Need?
- LESSON 10: SMALL, SMALL, BIG
- LESSON 11: Keeping It In The Field
- LESSON 12: Going For The Gold
- LESSON 13: Checking on Subtraction
- LESSON 14: NO FLIPPING SUBTRACTION
- LESSON 15: Assessment