Lesson Subject:
Math
Lesson Topic:
Understand and apply estimation strategies to predict or determine the reasonableness of answers in situations.
Grade Level:
Grades 3-5
Learning Target(s)/Objective(s) for This Lesson:
Given the problem and necessary materials students will gain and understanding of the word balance (relate this to the concept of equals or same as) and be able to apply it in situations.
Lesson Plan:
Problem: Jarrod decided to enjoy the fall day by walking in the park. Once there, he noticed that the animals were also enjoying the day by playing on a teeter-totter. Jarrod watched intently as the animals play a game. First, there were 3 squirrels on the left side of the teeter-totter and 3 robins and 2 crows on the right side. The teeter-totter was perfectly balanced (see figure 1). Then there were 2 squirrels and 2 crows on the left side and 3 robins and 3 crows on the right side, and the teeter –totter was balanced (see figure 2). Jarrod thought this game was interesting and he wondered aloud, “what could balance just one squirrel?” Help Jarrod answer this question by carefully investigating the balanced teeter-totter in figures 1 and 2 to determine which animal or animals could balance the squirrel in figure 3. Explain your solution. Is there more than one solution?
Given the problem above, students will begin to understand that an equals sign sometimes is implying that there is a balance between the left and the right side of the equations (or in this case the teeter-totter), and that it doesn’t necessarily mean the answer is coming after the equals sign.
Materials:
- Cut outs of crows, squirrels and robins for each student to work with
- Posters of figures represented in article
- Paper teeter-totters for each student
- Worksheet to figure out figure 4 in article
Lesson Opening:
Attention Getting Device (AGD): Alright boys and girls, we’re going to do a fun math problem. It’s going to start with me reading a little story which includes the problem, and then we will break up into small groups of 4. (If the students already have small groups, then I will use the pre-existing groups, if not I will have them count off and delegate where the different groups will gather afterwards. I may encourage them to write this information down, so they can focus on the story.)
Explain teeter-totter manipulative by showing it: Explain- we are gong to use this teeter totter and work together to find combinations of animals that balance each other on the teeter-totter. In the end it is going to be important for us to find out which animal(s) balance with only 1 squirrel.
Define balance: the same amount of weight on both sides. (First have kids give definition then verify by giving this one).
*Explain that all the crows are the same weight, all squirrels are the same and all the robins are the same.*
Check for Understanding (CFU): Then… “Is it correct to say that if the two sides are balanced then they are equal? Why or why not?”
First, no matter what they answer have them state what it means to be equal. Then go from there. Equal: having the same amount as another (two side of the teeter-totter).
!!* GET ALL ANSWERS BEFORE VARIFYING THE RIGHT ONE*!!
Have students recite their understanding of the word equals. Then reiterate to them that it doesn’t mean that on the right side of the equals side there is always going to be an answer.
Lesson Body:
“We are gong to be working with squirrels, robins, crows and a teeter-totter. We are going to read an story about a boy named Jarrod and help him have some fun in the park.”
I will now give the students a handout of the problem so they are able to follow along as I read the problem aloud.
After reading the article: CFU: Q: What are we supposed to help Jarrod with in this problem? A: What animal(s) it takes to balance or equal on squirrel.
Think aloud: I DO:
“Well first I am going to gather all the information I know about this problem. I know from reading and from the figures that 2 squirrels balance or equal 2 crows and 3 robins. I also know that 2 squirrels and 2 crows equal 3 crows and 3 robins."
WE DO: Ask the class: What other information do we know? How do we know that? (Write on the board)
Ask the class: CFU: “So what happens to figure 2 if I take 2 crows away from each side? Does it still balance? Why or why not? How do you know?"
THEY DO: By working in pairs let’s see what animals(s) can make the teeter-totter in figure 3 balances.
CFU: How else could I have made that statement? What is an important word that we have been talking about today that could mean the same thing?
EVERYBODY! (Equals?) We will come back together to share and test our ideas. Please use the crows, squirrels and robins I gave you so you can show, and others can see your answer.
Once the rations have been figured out, the students will work again to figure out figure 4, which they will then explain to the class as well.
Assessment: Make up your own teeter-totter problem and draw a picture to go with it to share with the class using the crows, squirrels and robins telling us why both sides of your teeter-totter are equal. (They will then be hung on the wall).
Lesson Closing:
So just to repeat the import and words that we learned today; can anyone tell me those tow special words we learned today? Equal and Balance! Everybody! Equal and balance in our case today meant that for the teeter-totter to balance they had to have an equal amount of weight on both sides. Who can explain that in another way?
Lesson plan adapted from:
Mann, R. & Hartweg, K. (2002). A Walk in the Park. Teaching Children Mathematics, 9, 57-58.
You must log-in or register to view and download attachments (4). Membership is free! Join Now!
Attachments: handout/worksheet, crow sheet, squirrel sheet, robin sheet
Class Time Needed:
30 minutes - 1 hour
