Scale drawings are a relatively fun topic to teach. Students grasp this concept more easily than some because it is very visual. I am going to share with you how I teach scale drawings using “I Can” statements as my guide.
What I Want My Student to Do with Scale Drawings…
When teaching students about scale drawings we want them to understand proportions. We want them to be able to look at a situation, set-up a proportion, and solve for an unknown value. Ultimately, we want students to be able to explain what they are doing and have a deep understanding of how scale works.
I Can Statements
When I sit down to plan a unit I chunk out the lessons through writing “I Can” statements. I use these “I Can” statements to drive my lesson planning and to guide my students throughout the daily lessons. Teaching students to understand scale drawings is no exception. This year is my first time teaching this topic. We usually have about 4 days to teach a topic and I work with a group of students who struggle with math. He is the list of “I Can” statements that I came up with:
- I can solve a proportion with a variable.
- I can read a scale drawing problem and set-up a proportion.
- I can explain my answer in a scale drawing problem.
After I had these objectives ready, then I knew what I was going to teach. It gave me a road map and a path of how to get my kids from here to there.
Keeping Track of Their Learning
I have my students keep track of their own progress through the “I Can” statements. We keep objectives, notes, and reflection in our interactive notebook. For the first page of the unit my students write the objectives for the unit (for a free copy click here). At the beginning or end of each lesson we go back to our objectives page and review our objectives for the unit. My students evaluate their understanding of the topic on a daily basis. This practice helps them to understand what they are trying to learn and if they are learning it.
I Can Solve a Proportion with a Variable
I realized that this a prerequisite skill that students have to have before they start to work with scale drawings. There are a couple of different methods that my students had learned to solve proportions with a variable. What I realized in the end was that it is a 2-step process of multiplying diagonal and dividing by the remaining number to get the value of x. This is a skill which means we are working toward automaticity.
My students struggle with many basic math concepts. Through a variety of practice for a few days the majority are able to complete this repetitive process with just a calculator. It did become automatic for most of them. It is great to see how confident they have become with this skill.
I Can Read and Set-up a Scale Drawing Problem
Students need to be able to read a story problem and identify the proportional relationship involved. They need to be able to organize the information from the problem and not be random about their problem solving. Here is an example of how I have them set-up the problem.
As you can see I have them put the drawing, or the smaller measurement on the top and the bigger measurement on the top. I have them line it up on the other side of the proportion the same way. There are other ways to set it up, but with only a few days to master this topic I just show one way. If you have fast finishers you might want to show them a different way.
I Can Explain My Answer in a Scale Drawing Problem
Students love to show how good they are getting at a new concept and sometimes they don’t know what they are actually doing. This is why I added this as an objective to this topic. Students are required to write a sentence that describes what their answer means. Their sentence needs to have good grammar and show mathematical reasoning. (See picture above)
Misconceptions or traps for students
I think the biggest trap for students is for them to keep the actual lengths and the drawing lengths straight. There are different ways for them to organize the information but I would just teach them one way. Remember that when students are new to something they can get confused with information overload. Their brains need time to think through what they are learning. Be cautious about how much info you give them at one time. If the topic comes easy to a few students, then you might want to show them additional ways of setting up the proportions.
You can assess this topic through multiple choice and open-ended questions. I have students close read a story problem and highlight the key parts. Then they set-up the problem, solve, and write a sentence that explains their answers. Some (many) students don’t want to write an explanation. They are used to showing a right answer and moving on to the next question. This part of the process is essential and is a really easy way for you to see if they are getting it.
If students are struggling with the writing aspect you can always give them sentence stems. Sentence stems is a method I brought with me from my days as an ELL teacher. They are great for struggling students, ELLs, and students on IEPs. Here are some sentence stems:
- The actual length of the…
- In this problem _____ inches is the ________________.
- In the drawing the height of the…
- If the model is __________, then the __________________.
- According to the situation in this problem…
In addition, sentence stems or fill-in the blanks are essential for some students because they lack the necessary writing skills.
By chunking the learning into three small parts students will be able to move from one to the other easily. Students will need instructional input, practice, feedback, and more practice to reach mastery with this topic. I want to challenge you to plan for this topic through a series of “I Can” and use them with students as self evaluations. So, if you are looking for questions that are scaffolded like these “I Can” statements then check out our Scale Drawings Task Cards in our TPT store.
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