The warm up area and perimeter context gives a new contextual setting for area and perimeter. Students are shown a rectangular enclosure with chickens inside and are asked to figure out how much fencing is needed to keep them from getting out. I purposely don't ask what the perimeter is because I want to know if they are getting confused just by the vocabulary or if they are having trouble with the concept of counting to find the distance. If they can identify where the fence has to be, but try to multiply or add only two sides I know they need to spend some time "building" fences with some hands on manipulatives. If they try to add only two sides I may also highlight two sides and simply ask if the chickens can still get out. This might be enough.
The second problem shows an enclosure with goats and asks how much grass the goats will eat. Some students may just say "all of it", so I would ask how much that would be. If they add all the sides I ask if the goats only eat around the edges of the yard. When they say no, I ask what they have to do to calculate the entire amount of grass covering the inside of the yard. It may help to have them use a highlighter to show where the grass is and have them highlight the entire area inside the yard.
When we go over this we talk about the difference between surrounding and covering, for example surrounding the chickens with the fencing and covering the entire area with grass and how those measurements look different. One measurement is just a line and the other is two dimensional or "square area".
This assessment perimeter or area is similar to a homework assignment they had in an earlier lesson providing contextual scenarios in which area and perimeter might be used. I still expect some confusion about area and perimeter being different types of measurements, one and two dimensional. I will use the results of the assessment to form new math family groups for peer instruction and additional work with manipulatives.
This homework border problem extension assignment is an extension of the border problem from two earlier (border problem) lessons. Here they are given different patterns for a tile floor using two different kinds of tile. Students are asked how many of each type of tile are needed. The last problem asks them to build a tile border around an irregularly shaped pool. I expect this will be difficult for them and I want to see how many of them try to model the problems with a diagram. This will be their first introduction to using a scale model when we go over the homework tomorrow. I really want them to see the benefit of using a physical model (diagram) and start using it as a tool on their own.