The students will be using a problem from illustrative math to begin preparing for their final assessment on Geometry. I chose this problem because it uses a variety of content, but still supports their learning about Geometry. Students will first need to find the area needed to paint then find the cost of paint in gallons.
To start this problem, I’m going to give the students 5-10 minutes of struggle time. Struggle time is their independent thinking time. They can’t ask questions or get help. They need to make sense of the problem on their own and try something. When struggle time is over, the students will then get to talk this over with their tablemates. I will be targeting students that have nothing on their paper. These students will need to ask me a mathematical question in order to help them get started.
They will need to know that they will be painting 2 30 x 50 ft walls and 2 50 x 80 ft walls. They will need to add these areas together to find the total area needing paint. To help students reach this understanding, I would encourage them to create a visual to represent the barn (rectangular prism). They will also need to come to the understanding that only the 4 walls and not the roof or bottom of the barn needs painting.
Next, they will need to find out how much it will cost to paint the barn using the square footage they found. Students can use a ratio table as a tool (MP5) to help them organize the information. There is some reasoning in this problem because 18 gallons won’t be enough and 19 gallons will be too much (MP3). Students should give you the reason why they would need to choose 20 gallons. The ratio table will get them close to the answer so they will need to make a reasonable statement about the amount of gallons needed.
Finally, they will need to find the cost by multiplying the amount of gallons by $28/gallon to find the total cost (MP4).
Solution: It will cost Alexis $532 to paint the barn.
Tools: DO NOW problem
I chose to use an Around the Room for our review because it does give me the opportunity to work at a problem with small groups . For example, I will choose the problem that I feel will be the hardest or one where I’m looking for a specific strategy and I will position myself near that question. This way, when the students come to that problem I will be there to help, enrich, or question.
The Around the Room is in a power point. The slides can be printed to use for each question.
Question 2: I may ask the students to use the area formula for a rectangle to solve. Students can explain to me how they would make the parallelogram into a rectangle and then find the l x w.
Question 4: I may ask the students to explain to me how to use the area formula for a rectangle to find the area of a triangle.
Question 8: Students may need assistance with this. Ask students what they can do to help them find the surface area of this rectangular prism? Students should know to create the net.
Question 14: Students will need to know that they are using ½ cm blocks to fill this rectangular prism. Have them give you one strategy to use?
This activity can also be used as a Numbered Heads Together if you are looking for more of an informal assessment of the entire group.
Using either strategy supports:
MP1: making sense of the problems.
MP2: what do the numbers tell me?
MP3: justifying their solutions with a partner.
MP4: Modeling the mathematics with formulas
MP5: using models to help with the math.
Tools: Around the room questions power point.
I’m going to give the students some time to start on their study guide. The study guide is set up so that they are reasoning about their math using words (MP 6). They will be explaining the “how” part and then using this to apply it to a mathematical model. Since this is a little different than what we normally do, I wanted to give the students a chance to start on this while they have the support of a teacher. I always like to say to the students “look through the study guide and find the problem that you feel will give you the most difficulty. Try this problem first because you have support from your tablemates and the teacher.”
I will answer any questions the students have during this time.
Tools: Geometry study