Creative Teaching Tips and Ideas for Perimeter and Area Part 2 (EP 38)

Creative Teaching Tips and Ideas for Perimeter and Area Part 2

Hello, everyone, and welcome to another episode of Elementary Math Chat. Today, I’ll be covering the second half of my unit on perimeter and area. So, if you missed last week’s episode, make sure you go back and listen because that is when I covered the first half.

Those lessons were more of the basics with perimeter and area. We talked about how to find the area, how to find the perimeter, and how to find the area of combined rectangles.

This week’s lessons are going to be a little more challenging to teach because they focus more on the problem-solving areas along with multi-step questions. So, I’ll be taking you through these problem-solving lessons, and also I will share what I did on my review day because I have a lot of great tips to help your kids prepare for the test.

All right, so let’s go ahead and start with my fourth lesson in this perimeter and area unit. This one was on finding the missing dimension with perimeter and area, and I did split this into two separate days. So, I focused on perimeter on the first day and area on the second day. 

I’ll go ahead and start with perimeter since that’s what I taught on the first day. I actually really enjoyed teaching this lesson, and I think my kids enjoyed it as well, as long as they were getting the hang of it. 

But there were two different ways that I taught them to find the missing dimension. So, if they struggled with the first way they could use the second way. So, let me walk you through an example using that first method. 

This one’s kind of like solving a simpler problem, because instead of using the number that you’re given for the full perimeter, you’re going to cut that number in half and use that one instead. So here’s what that would look like.

Let’s say the problem tells you that the perimeter of a rectangle is 50 inches, and the length of one side is 10 inches. Again, the very first thing I had them do was to take that perimeter and cut it in half. 

What’s half of 50? Half of 50 is 25. So, that means that two sides are going to add up to 25 , and we already know the value of one of those sides. So, that makes it really easy to figure out the other side. 

You can either subtract 25 minus 10, to get 15. Or you can think about it as an addition equation, 10 plus what number is 25.

See how much simpler this is? We’re no longer thinking about four sides adding up to 50. We’re just thinking about two sides adding up to 25.

So, that was one way that I taught them to find the missing dimension. The other way was to use a part-part-whole model. I know you’ve probably use that for addition and subtraction. But you can also use it with perimeter. 

The perimeter will go on top because it is the whole. It’s the distance around the whole figure. And then the four sides of the rectangle represent the parts, and those go on the bottom. 

So, once we put the 50 at the top of the model, and we also put the 10 in one of the parts, they realized, well wait a minute. In a rectangle, opposite sides are equal. So, if one side is 10, there’s going to be another side that equals 10. 

So, all of a sudden, this becomes a very simple subtraction problem. They can see that they have a perimeter of 50. So far, they can subtract 20, and they have 30 leftover, but they’re not going to answer 30, because they see they have two sides that equal 30. 

That’s something that gets overlooked when they don’t have the model. But the model will make it very clear that they have two sides that equal 30. So, each side equals 15. 

So, this option is a really good one for your visual learners and for those who struggle with mental math, because I think that first method is really meant for those who can do it mentally. 

I also like that it’s easy for them to check their answer at the end. You know, when they have all of their numbers in the model, it just looks like an addition problem. So, they can add the four parts of the bottom to get the perimeter, and if they’re equal then they know their missing dimension was correct. 

Just in case you need more information or you’re not familiar with part-part-whole models, I’ve got a few additional examples in the show notes, and I’ll have pictures that go along with those. They’re kind of hard to explain, but they’re really easy when you see the model.

I will also link the set of task cards that I used for this lesson. They were a great supplement to the textbook because I couldn’t use the book. The book combined both perimeter and area together, and I was only teaching perimeter on this day.

But these task cards were great because they all had a missing dimension, and they were all real-life objects that were either a square or a rectangle. So, we were looking at street signs, muffin pans, chocolate bars, and pool tables. Obviously, this is much more exciting than just looking at regular squares and rectangles. So, it made this lesson a little bit more engaging. 

The last thing I want to share about this first day was what I did for small groups, because it was super easy, it was very low prep, it provided a little challenge for those who needed it, but also additional support for those who were still struggling. 

All I did for this was I wrote three sets of questions on my whiteboard, and they all had a different level of difficulty. The first set was a little bit easier. They all had whole number dimensions. So, those were good for the kids who were either struggling or just needed a little more practice before they became proficient. 

For example, one problem that I wrote gave them a perimeter of 60 and a length of 20. So, that missing dimension would be 10. 

The other two sets I wrote were challenge questions, and these dimensions included fractions, decimals, mixed numbers along with whole numbers. 

So, for my second set, they might have a perimeter of 40 and a length of 10 and four-eighths, so that missing dimension would be nine and four-eighths, or nine and one-half if they want to put it in simplest form. 

In my third set, I included both fractions and decimals. So, this was by far the most challenging set. An example from this set would give them a perimeter of 38.6 and a length of 12 and nine-tenths in fraction form, and so that missing dimension would be 6.4. 

You probably know this by now, but writing problems on the board is one of my go to small group activities. Number one, it’s quick. So, if you’re short on time, it’s a really good one to use. And number two, it’s such an easy way to provide various levels of difficulty. So, if you need an idea for this lesson, definitely pencil this one in. 

So again, all of this I did on the first day of missing dimensions. The following day, I repeated this lesson but with area. I used the same set of task cards with real-life figures like pillows and smartphones, but this time, I did not require them to draw a model. It’s really not necessary with area. It’s a lot easier for them just to use the formula, and a lot of times they can use basic facts and mental math.

So, we just used the formula area equals base times height, and we either multiplied or divided to find the missing dimension. So, the questions we did in whole group were pretty easy, and I preferred it that way. I wanted to keep it simple. So, they learned the process, and then once we got to small groups, then I could really up the difficulty level.

So, just like I did with perimeter, I wrote three sets of questions on my whiteboard, and they all had a different level of difficulty, but they all required long division to solve.

An example from set one is an area of 72 square inches and a base of three inches, and they had to find the height. That one’s a little easy, and some might be able to do it mentally. But if they were able to do that mentally, I had them move up to a different level because that was too easy for them.

An example from set two is an area of 423 square centimeters and a height of three centimeters, and they would have to find the base. Set three was my most challenging, and they would include an example like an area of 4370 square yards and a height of nine yards, and they would have to find the base.

Again, such a simple math center and a great way to incorporate long division in this lesson. And remember, take a picture of these questions before you erase them and put them in your lesson plans, and then next year it’ll take you just a few minutes to set this activity up.

Alright, let’s move on to the fifth lesson in my area and perimeter unit. This was a problem-solving lesson on area, and these questions all had them subtract one area from another. Like, if they were painting a wall, but they didn’t want to paint the window.

Now, I don’t know how you’re gonna feel about this, and I don’t know if you feel comfortable doing this, but I actually let my students use calculators for this lesson. The reason I did this is because I wanted their focus to be on learning how to solve these problems, and I didn’t want the rigor of the multiplication to get in the way of that, because it could.

If they were stuck on figuring out what 25 times 82 was, that would be their focus instead of learning that in these problems they need to subtract the area of the smaller object from the area of the larger object.

So, the calculators not only helped this lesson flow a little bit better, but it took the focus off of the multiplication, which by the way, we had already been practicing a ton in this unit, and it put the focus on learning the steps that they needed to take in order to solve this type of problem.

Also, my students were able to use calculators in one section of the state test, and they were typically problem-solving questions like this. So, that was another reason why I thought it would be good to use them with this lesson. So, consider that if you do use calculators in state testing, this would be a good lesson to pair them with.

The final tip I have for this lesson is to make sure as much as possible, you are connecting these questions to real-life scenarios. I know I’ve seen questions on tests or worksheets where it gives them a gray square and then puts a white square inside of it, and it has them find the area of the gray portion. Well, of course, they’re going to struggle with this. It is way too abstract.

So, in order for them to understand how to solve these problems, we have got to connect it to something they’re familiar with, and it doesn’t have to be complicated. It can be as simple as labeling it as a garden or a swimming pool or just something realistic that they can connect these ideas to.

It’s even better when it’s within an actual word problem, and that’s exactly why I used the workbook for this lesson, because every single question they were answering included context around a garden, or wallpaper, or a playground. Nothing wrong with using the textbook. If it’s a good lesson, I’m all for it.

So, that’s going to take us to the final lesson in my area and perimeter unit. This was a review day, and I actually ended up spending two days reviewing for this test because there was a lot to cover. One of those days I went through the chapter review with them. So, I’m going to share what I did on the second day.

I started this review day with a few area and perimeter riddles. These are so much fun and they are a great way to begin this lesson because they require students to think about both area and perimeter. I finally got around to posting these on TPT. I kind of forgot about them, honestly, and I was researching for this episode and going through all of my old lesson plans and activities. And I realized, oh my goodness, I never posted these!

So, they are on TPT now, and here’s what they sound like. One riddle says, I am a rectangle. My area is 24 square inches, and my perimeter is 20 inches. So, it gives them clues about their area and perimeter, and then under that it says, what are my dimensions, and then it tells them to label my sides and solve the equations to check.

Now, it says label my sides because on each one of these, there is a rectangle or square on the slide, and they have to label the length and the width or the base and the height, whatever you call it. And then they check their answer by putting it in the equations. So, there’s an area equation and then there’s also a perimeter equation.

So, they guess by labeling the figure, and then they check it by putting it into the equations. I will have these linked in the show notes if you’re interested, and there are a couple ways you can use them because they are printable and digital.

I used the digital version, the Google Slides version, and that way my students could type their answers in themselves when we went through these, but I only did four of these together and there are 10 of these.

So, you could take the ones left over that you don’t do, and you can print them and put them around the room for a gallery walk or put them on a choice board. There’s actually a recording sheet that goes along with this, and it has the rectangles on there. So, that would be something fun you could do after your whole group lesson.

Again, that’s what I did for my lesson warmup. For the main part of my lesson, I used an activity from the program Freckle, and I think a lot of you might have this program. So, if you do take a look at the IBLs, and you’ll want to look for the one that’s titled “The Gold Rush.”

It is such a neat and engaging lesson because it ties in The California Gold Rush with perimeter and area, and it’s perfect because it never asks them to find the area or find the perimeter.

Instead, it’ll ask them something like how many feet of fencing will they need? Or how many square miles can the miners cover? That’s exactly the type of question that they need practice with. The ones that don’t say, what is my area or what is my perimeter, but instead give them context clues for them to decide if they’re supposed to find the area or the perimeter.

You know, it took me a few years before I discovered those IBLs, and after that I used them all the time. So, if you have Freckle, check out their IBLs. By the way, I didn’t mention this. That stands for inquiry-based lesson. They are so much fun.

All right, well, the last thing I want to share about my review day is what my students worked on for their independent activity. I know I’ve mentioned Boom Cards quite a bit in this podcast, and they are hands down my favorite resource to use for a review day

The reason being is that they get immediate feedback after every single question, and that’s exactly what they need to help them prepare for a test. What’s unique about this set that I created is there are 20 questions, and there are questions over every single lesson in this area and perimeter unit.

So, it’s a really good review before the test, and that’s exactly why I created them. I always had a hard time finding activities for review day, and I wanted them to be fun and a little different from the questions in the book. My kids love Boom Cards, so these were perfect.

I will not only link the Area and Perimeter Boom Cards that I used, but I’ll also have the bundle linked if you want to take a look at the other sets that are included. There are 13 sets included. I’ve got one for every unit, or every chapter, if you want to call it in fourth grade. And again, they are such a great way to review for a test or even for state testing. I know I’ve mentioned them a couple of times when it comes to state testing.

Well, we have made it to the end of my perimeter and area unit. Hopefully, you have a couple of new ideas that you are excited to try with your students, and don’t forget to check the show notes because everything I mentioned in this episode will be linked there for you.

All right, well, let’s go ahead and wrap up with today’s teaching tip of the week. Today I’m going to tell you about one of my favorite math games to play, and this game is called SKUNK. You know, for years, I never really thought about the name of this game. But I think the reason they call it SKUNK is because it stinks when you lose. One day, I just randomly thought of that, and I was like, wait, I think that’s probably why they call it SKUNK!

But anyway, I love this game because it’s unpredictable. There’s a lot of risk involved, but it’s also a great way to practice multiplication facts, as well as probability.

To start the game, you will need to put the letters SKUNK either on a whiteboard or a piece of paper, and each letter represents one round. So, there are five rounds in the game of SKUNK. Their goal is to earn as many points as possible and hopefully be the person at the end with the most points.

The only materials that you’ll need are dice, and you’ll need two of them. I always used the digital dice so they could see what numbers I was rolling, but you could use regular dice and just tell them the numbers that you’re rolling if you want to do that.

Each time that you roll, you multiply those two numbers. So, let’s say you roll a three and a six. Three times six is 18, so they earn those 18 points, and they write them down under the letter S.

Now remember, I said there was a lot of risk involved in this game, and here’s why. If at any point you roll a one and they are standing, they lose all of their points for that round. So, they earn a zero for that round. So, what this means is if they want to secure those points that they just earned, then they have to sit down, and they’ll have to wait for the next round to begin before they can earn more points.

So, let’s say your next roll is a two and a five. Two times five is 10. Only those who are standing get those additional 10 points. If they sat down, they only have 18 points. So, they add those 10 points to their total, and then they have to make a decision. Do they want to stay in the game and go for more and risk losing it all? Or do they want to sit down and secure the points that they have?

So, every single round, there’s risk involved, and they get this huge adrenaline rush as they decide whether to remain in the game and go for more or to sit down and secure their points and play it safe.

And of course, the person at the end with the highest total is the winner of the game. They do say if you roll two ones then the entire game is over. But I never did that. I’m not going to end the game if I rolled two ones and I’m only at letter K. The game is too much fun to end it there. I just ended that round and then went on to the next round.

Now, I will warn you it can get a little bit rowdy, but it’s so worth it. It’s so much fun to play. I played this several times that last week of school and my students always loved it. I’m sure yours will as well.

Well. That is all for today’s episode. I hope you enjoyed it. Have a great week and I will see you next Tuesda