# Quadratic Functions – Sample Lessons and Resources

I am starting a monthly feature where I will be focusing on some specific math content areas and providing some resources, in the form of how-to videos (both calculator and Classpad.net) and some ready-to-use math lessons (either PDF or links, depending on the tool used). I know math teachers are always searching for resources that will help them provide more open-ended math activities, where students are collecting and using data, using multiple representations to analyze and solve problems, and where students have to make decisions and support their decisions with mathematics. And integrate technology as well! So, at least once a month I am going to be picking a math content to focus on and provide some technology options as well, sometimes both calculator and online, and sometimes one or the other, depending on content.

This week I would like to focus on quadratic functions and helping students use a real-world context to work with quadratics. I am going to utilize Classpad.net, which is FREE web-based dynamic math software where I can do statistics, graphing, and calculations in one place (geometry as well, but for this activity, our focus does not include geometry). I am using this technology for a few reasons:

1. It’s free, so all of you should be able to access the created activity, including your students, as long as you have a mobile device with internet access.
2. I am able to create a complete activity (i.e. directions, tables, graphs, and place for students to show work) in one place and then share it easily via URL.
3. Everyone who opens the activity can create their own copy of it (as long as you have a FREE account on Classpad.net) by duplicating into their account. Then you can modify, answer the questions, etc. and create it’s new URL to share with others (or for students to share with you). To learn more about duplicating activities, click here.

The Problem

You are fencing in a rectangular area of your yard to create a garden. You have 36 ft. of fencing, of which you plan to use all. You can cut the fencing into whatever lengths are needed, as long as you use all 36 feet.

What dimensions should you use for your garden?

The Lesson

I have created a shared paper on Classpad.net called Quadratic Functions – Area of a Garden which you can access by clicking on the title. The idea behind this problem is that there are actually multiple solutions since the question is rather vague. I did NOT ask what is the largest garden, so students can work on collecting and analyzing the data and come to different conclusions depending on what they think is important. Some might choose largest area for the garden, some might choose largest perimeter, some might only want a rectangle some only a square, etc. By leaving the question a little more open, you are giving students a chance to explain their reasoning and come to multiple solutions based on this reasoning.

This is a video that shows using the activity and parts of doing the activity to get a feel for how this looks with students. I would recommend students working in pairs or small groups (3-4). All students can be recording on their mobile devices, or if you have one per group, choose a recorder.

# Complex Numbers – Support for Calculations

I received a question on one of my Youtube video posts on the Casio Fx991 scientific calculator asking if it was possible to do complex number calculations on this calculator. The answer is of course yes – which then prompted me to make a quick video today on exactly how to do that with the fx991. See the video below:

This of course then made me think of our other technologies and that perhaps I should show how to do complex numbers with these tools as well.

Here’s the steps on the graphing calculators (any of the Casio models, since they all basically work similarly – the beauty of Casio, the buttons are relatively consistent). This example uses the CG50, but see fx-9750, fx-9860, etc).

And finally, on ClassPad.net, the FREE online math software that does it all – statistics, geometry, graphing, and of course calculations. (You can sign up for a free account (ALWAYS free) – here’s a quick how-to).

The question of course arises, when are we even using complex numbers? Or why do we need them? As I never really taught math content that required students to utilize complex numbers, I don’t feel I am able to answer these questions with authority, so I did a bit of research. For one, if we just go from a ‘content/standards’ perspective, if you are in states that incorporate The Common Core Math Standards (or a version of, whether renamed or not), then it is actually part of the High School: Number and Quantity standards which state, “Students will…”:

• Perform arithmetic operations with complex numbers
• Represent complex numbers and their operations on the complex plane
• Use complex numbers in polynomial identities and equations

But, that of course doesn’t really get at why do we need them. So here are some things I found in my search for this answer. I admit I can’t explain these any more than just listing them, but it at least points to places where complex numbers are in fact important and needed.

• Complex numbers are used in electronics to describe the circuit elements (voltage across the current) with a single complex number z=V+iI
• Electromagnetic fields are best described by a single complex number
• People who use complex numbers in their daily work are electrical engineers, electronic circuit designers, and anyone who needs to solve differential equations.

Hopefully this is helpful to those of you who are in fact doing complex calculations for whatever reason!

# The Power of Math Exploration

If I had a dollar for every time I hear “I would do more hands-on, inquiry, problem-solving, collaborative learning, in math class if I ________________________ (insert any one of the following):

• didn’t have as many students
• didn’t have to get through the ‘curriculum’
• had students who would actually talk
• if I didn’t have to make sure they were ready for the test
• if I didn’t have to review all the things they didn’t learn from last year…..
• ….the list goes on…….

I would be a very wealthy woman. What is mind boggling to me is there is so much research out there that shows students do better when they learn for understanding and not for memorization, which means learning through context, through inquiry, through problem-solving, through struggle. Time is one of the biggest ‘road-blocks’ teachers throw out there, and granted, there definitely is a time crunch to get all the content in before those dreaded assessments. What I try so hard to get across to the teachers I work with, is that you can  save time by taking time – you actually can ‘cover’ more ground by teaching from a more contextual, experiential, problem-solving way. As students make connections and problem-solve, they are able to learn more efficiently and more than one concept at a time because they are working from a connected-math view point instead of the single-skill/concept at a time approach we traditionally provide.

An example from Geometry: (this is using Classpad.net, free math software)

Concept – identifying polygons, and then what’s the difference between congruent-sided polygons versus regular polygons (identifying what a regular polygon is).

Activity: Using the drawing tool, have students draw examples of 3-side, 4-sided, 5-sided (and more….) polygons.  At least 2 of each kind that look ‘different’. Can be convex or concave

• Have students compare their shapes noting similarities and differences and coming up with definitions – attaching specific words to their definitions like convex, concave, closed, etc.
• Now have students use the arrow tool, and select one of their triangles, and the Adjustment menu to make all sides congruent. Then, choose a second triangle and Adjustment and make the shape a ‘regular’ polygon. What do they notice? Have them measure sides and angles and compare to others.
• Do the same for two different 4-sided figures (so Adjust congruent, then adjust regular), the 5-sided, etc.  Each time compare the two on their paper, and then compare to others, and try to come up with what the difference is between congruent-sided polygons and regular-polygons.
• Come to group consensus, and by the end of class students have manipulated, explored, collaborated and defined several things: polygons, convex polygons vs. concave, triangle, quadrilateral, pentagon,….regular polygon, congruent sides, etc.

An example from Algebra: (this is using CG50 Graphing Calculator (CG10 is similar):

Concept: Parent Function and Vertex From of a Parabola

Activity: Students graph the parent function of a Parabola (y=x^2) and then graph another in standard form using variables for coefficients.

• Have students use the modify feature of the graphing calculator to animate the different coefficients (one at a time)
• Observe what changes in that coefficient does to the parabola by comparing the modified to the parent
• Make conjectures and compare with other students till consensus is reached.
• Do this with all the coefficients.
• Have students then test out their conjectures by providing them several equations of different parabolas and, based on their conjectures, determine the shape, direction and location of the parabola BEFORE they do anything, and then test their guesses by entering in the calculator.
• Time saver: Doing this activity with linear equations first will then give students a general understanding of transformations of functions which they then extend and solidify with quadratics, which then can be easily extended into other equations, like the absolute value function. Time saver!

Obviously I am using technology here, because technology allows for conjectures to be made and tested very quickly. But technology is just a tool that is appropriate in some instances, but there’s so much that can be done without technology as well. You can make math much more of an exploration just through your own questioning (i.e. why do you think? can you explain that more? Are there other ways to do this?) and by providing students a chance to puzzle things out on their own, ask questions, use tools (so objects, paper, pencil, etc).

One of my favorite things to do is to provide them with a situation that has lots of information, but no question (basically, find a rich math task, but don’t give students the question(s)). Students then write down all the things they notice, such as quantities, relationships, etc. and then come up with their own wondering’s and questions. Then you let them choose a path they want to explore (this works well with small groups or partners). Usually it ends up that there are several different questions and solutions generated and explored using the same information. When students then share their findings, you find that there is a lot of math going on, which leads to some really interesting class discussions – some you yourself might not have thought of. You can then maybe even give them the question that might have been given in the problem – by that time students may have already explored it and if not, by now they have a real sense of what information in the problem will help them and they are more willing to actually solve the problem.

The key here – students only become problem-solvers if they are given the opportunities to explore math, make their own connections, and collaborate with others to verify their thinking. The more you give them opportunities and provide tools and resources and challenging problems, the more efficient they become at using math, connecting math concepts, and viewing math as a connected whole instead of isolated skills and facts. Take the time….it’ll come back in the end.

# The Power of Visualization – Modifying Graphs with a Graphing Calculator

I have had some great discussions with teachers in my courses lately about the power of providing opportunities for students to see and manipulate mathematics as a way to test out their ideas, play with patterns, and develop their own rules and understandings. Visualization, manipulation, experimenting – all contribute to students developing deeper understanding and their own ‘algorithms’, and because of these contextual experiences, they are much more likely to recall how to do a math process than if they were just given the rules/algorithm to memorize.

In a recent final reflection, one teacher wrote, “As a high school teacher, I have always stayed away from using manipulates for fear they were “too elementary” for my classroom.”  This attitude – that older students don’t need those physical objects or need to see – that they just need to  memorize rules and practice – is sadly still prevalent today. Which is frightening really. I experienced these same attitudes and beliefs over 2 decades ago when I was teaching in  middle and high school, and bringing out my two-colored chips, algebra tiles, and Sketchpad. Allowing students to play with math, to use physical objects, and virtual objects, to represent the math and then be able to manipulate change and see what happens was always considered ‘babying’ them. Clearly that attitude is still going strong today, since as you read above,  I hear it in the courses I teach with current classroom math teachers. This despite even more tools being available to provide a way for students to experiment, play, discover, create and find the mathematical patterns and rules themselves. The tendency to just give them the rules and the process and the definitions and have them memorize and regurgitate is still very much a part of our mathematical education. What we really want to do is provide multiple ways to look at and explore math concepts, so that when students ‘forget’, they have that experience where they built the understanding to recall where they can rebuild it again. Much easier to recall something they saw or something they physically moved and connected to than an isolated, memorized fact.

In most typical high school classrooms I visit and work with these days, it is rare to find physical manipulatives (more often in Geometry, but much more rare in an Algebra 2 or Pre-calculus class for example). But – there is almost always a technology tool – whether that be the teachers projector attached to the internet, or students on tablets/laptops, or more often the case, graphing calculators of some sort. Which means there is no excuse NOT to be providing students the opportunity to visually see the mathematics, and to manipulate and explore to come up with those algorithms they are often asked to just memorize. Meaning: use the technology for more than checking answers!  Use it to help students find the patterns and connections and create their own algorithms and definitions, use it to delve deeper into the math, to gain insight, to test out conjectures and really get a sense of what all those numbers and variables mean and how they interact with each other to change the shape of a graph and what that might mean in a application of that math in the real world. Use the tools to manipulate and see the math; technology allows for students to test a conjecture quickly, make predictions and check if they are right, and explore very large and very small numbers, etc.

As an example of this, I am going to use the Graphing Calculator App (for mobile devices), since I haven’t previously used this before in any of my videos, to show the power of visualization and technology to make conjectures and immediately test them with modifying features/dynamic math capability. You can do this on our hand-held Prizm series graphing calculators  (handhelds and emulators).

Additional Note: Try our FREE new dynamic math software that is web-based – perfect for tablets, PC’s, mobile devices: ClassPad.net

# Classpad.net Version 1 – Just In Time for School!

Welcome back to a new ‘school year’ (for some anyway). I’ve been on a bit of a hiatus the last couple months, working hard and doing a bit of travel. But, time to get back to it and what better way to start things off but with the launching of Version 1 of Classpad.net.

I posted about Classpad.net back in May, in my post Classpad.net – My Math Love-Affair Continues, This time I want to actually delve much more into what Classpad.net is and share some activities and images to give you a sense of the power of this web-based software. We’ve been in Beta-mode, where we’ve been fixing bugs, working on functionality improvements, and other things while teachers and students have been playing around with the software. Big shout out to all of you who’ve been giving us feedback – we’ve been updating and making changes and fixing bugs in large part to your input. Today is the launch of Version 1, so no longer in ‘test-mode’. Does that mean it’s done? Absolutely not! The beautiful thing about web-based software is that we are constantly improving and updating and adding features. It’s really in its infancy, with so much more growth and functionality and improvement on the horizon, which makes it even more exciting knowing this is only the beginning.

Great question. At it’s heart, it’s FREE (yes…forever) web-based, dynamic, math software. We call it ‘digital-scratch-paper’ because you can pretty much do whatever you might do when you pull out a piece of paper – i.e. write some notes, do a calculation, make a graph, create a table, draw a picture, measure something. As we know, there are lots of math software and tools out there – but most have specific purposes (i.e. only do statistics, only graph, only do calculations, etc.), so we end up having to use one tool to make graphs, another tool to create geometry constructs, yet another one to do some statistical analysis. And then, if we want to create an assignment for students, we have to use yet another tool to copy-cut-paste our various tables, graphs, constructs, and directions into a usable document. Classpad.net allows you to do all of that on one ‘paper’, which can then be printed (PDF), or shared (unique URL), or saved.  You can send this to students via URL (email or post on your website), students can make their own copy and do their work and send it back to you. It’s all there on one page – and, the beauty is, you can arrange and rearrange things on that paper as you want. To the right is a snapshot of a ‘paper’ showing all the stickies – i.e. text, calculate, graph, geometry, table/statistical plot. You have unlimited scroll and vertical space, and all objects are moveable – arrange and rearrange to your hearts content. You can title the pages and change the banner color to help sort and group content areas.

What Are The Components of Classpad.net?

You can pretty much do all the mathematics you need with Classpad.net for all K-12 curriculum content areas, including Calculus and AP Stats. There are some features that as of today are behind a ‘paywall” (i.e. nominal fee for the add-on app feature), but these are features that most K-12 teachers would NOT want students to have or necessarily need (re: CAS ability, allowing for solving equations or factoring polynomials, as an example; handwriting recognition, and a few others as we add in functionality).  But, here are the general components of Classpad.net, and with each there is a quick GIF showing some aspect of each component:

TEXT – text is just that – you can pull up a text sticky to write directions (for student homework/tests) or descriptions. You can also type in mathematical expressions/equations/terms in the text. Text stickies can be moved and resized as needed, color changes, and you can set a sticky for students to respond to (or students can add their own text sticky to write in answers and reflections as they work on things.

CALCULATE – as you would expect, calculate does calculations and so much more. You can define functions and lists, and use them later in graphs and statistical tables. Due to natural display, you can get exact answers. You can use function notation and shortcuts (see the ? at top right of Classpad.net for the function list). And, as with all the stickies, you can move the calculation stickies wherever you need them to be or pull them up whenever needed – all on the same paper.

GRAPH – again, you can graph anything – equations, defined functions, inequalities, integrals, etc. You can create sliders to move graphs and compare functions. You can find area under the curve, click on the graph to see key points, add moveable points to a function plot, look at the table of values, or plot from a table a values, make moveable lines for lines of fit. Comparing graphs is easy too – you can put graphs together or pull them apart to look at things separately. You can have multiple graphs on your paper – either merged or separate. You can add pictures to your graphs as well.

GEOMETRY – Yep, you can even add geometry to your page. We are still building out the geometry component, but right now you can do what you would expect with a geometry tool – i.e. create geometric constructs and specific constraints (perpendiculars, parallels, etc.), measure (area, length, angles, etc.), transformations including dilation, with features that are also unique (so you can construct conics, you can draw free-hand and then ‘adjust’ shapes and objects to have particular constraints. There’s the ability to create a rotational slider. You can create Hide/Show buttons and functions and expressions, and of course typical things like hide objects and change size, colors, etc. I am excited about geometry because I know it’s only the beginning and there’s so much more we are going to be adding.

STATISTICS – So much to do already, and still so much more to come with statistics. But, what’s the most fantastic part is you don’t have to go get a ‘statistics’ tool for students to be able to collect data, record it in a table, and then analyze that data. This could mean measures of central tendency, or standard deviation, or making different statistical plots to represent the data. Normal distributions, many types of regressions, box-plots, dot plots, histograms…so much there already and we are adding more in the future. As you would expect, we have a spreadsheet that can do calculations or use pre-defined lists (see calculate). You can then add functions to your statistical plots – so everything is all in one place for students to explore and connect.

Check Us Out and Share Your Papers and Experiences:

4. Our website – subscribe so you can start saving and sharing your work with others! Classpad.net

# #TheMathContest – Supporting Student Problem-Solving

My last several years in high school, I was a ‘roving’ teacher, meaning I didn’t have a classroom of my own, but switched classes just like the students. This made for a very challenging prep experience, and required me to be super-organized and self-contained on my little rolling cart. The rooms I ‘borrowed’ for my classes did allow me to keep an area for my students (to turn in homework and pick up missing work, etc.). In each class, my students had a portfolio (i.e. file folder), where they kept their work, one of which was the daily ‘warm-up’ problems.  These were basically a set of 5-6 problem-solving activities – some applications, some skills practice, some real-world scenarios, some puzzles, etc.  Students were expected to pick this up daily and work on these in the first few minutes of class, which gave me time to: a) get there; b) check homework; and c) set up for the class/lesson, etc.  It gave everyone a chance to ‘settle’. Students had a choice – they could do some or all of the problems by the end of the week, and I just checked portfolios and work at end of week. We would always discuss possible solutions the following week (and also they earned points for their efforts).

Needless to say, since I was providing these problem-solving experiences daily, I had to find lots of different resources for these problems, especially those that were more application and thought-provoking. Can’t tell you how many problem-solving books I purchased! There were other sources, such as The Math Forum P.O.W. (now no longer in existence, though their P.O.W. “s do still live on at NCTM), and even my textbooks had some great problems if you looked for them. The point is, it took a lot of effort to provide these challenges for my students. Obviously, I could have done it once a week instead, but for me, it served that duel purpose of focusing my students every day while I was en-route. My goal, and something I think all teachers should be striving for, is to provide students some challenges and problem-solving experiences on a regular basis – ones that may utilize prior knowledge or challenges them in different ways of thinking with new skills.

For those of you looking for such challenges, there is a new resource available from Ole Miss’ School of Education called #TheMathContest. It is actually a reboot of something Ole Miss did in the past, but it’s been revamped and improved, and now is sponsored by Casio Education and encourages the use of the new, FREE, online math software, Classpad.net that I talked about in my last post. Basically, new problems are posted each Monday, and each user can submit one answer per hour. Correct solutions earn points and you can view rankings on the website. Go to the link above to get more details on the contest. There are monthly rankings and annual rankings, which you can view online. How points are awarded is explained here.

This would be a great way to engage students and get them doing some challenging math, not to mention trying out the new software as well! If I were still in the classroom, I think I might add this as extra credit for students (for trying) and then maybe have a collaborative problem-solving time where we discuss possible approaches to the solutions after the previous weeks problem has ‘expired’.  Or maybe group students in ‘teams’ where they submit as a team? In any case, it would be nice to have a problem challenge already done for me each week, that’s for sure!

One thing Classpad.net is doing is posting video solutions to past P.O.W.’s which you can find on our Youtube Channel  Here is an example from May 7, 2018’s Problem of The week:

The Problem:  Find the 1-millionth term ins the sequence {1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, ……}

There is still time to try this weeks #TheMathContest Problem of the Week for May 14, 2018!  And check out the rankings – you will see students from countries all over the world who are participating.

# ClassPad.net – My Math Love-Affair Continues….

I am a lucky woman.

For my almost 30 years in education, I have loved what I do. Teaching math, helping others teach math, finding amazing tools and resources that make learning math engaging and exciting – my ‘work’ is a labor of love. My love-affair with mathematics and teaching has been influenced by many experiences and people and has led me to yet a another new adventure in my quest to help others love and appreciate the beauty of mathematics – Classpad.net,  a free, web-based software that I have been directly involved in, from conception, to development, and now, to public release and hopefully, viral usage!

Some of my Key family

It’s been a weird path of growth, with connections leading to new opportunities, and more connections, and more opportunities. As a new teacher, and also working on my masters at VCU in VA, I worked under John Van De Walle, who started me on the path of making mathematics hands-on and visual and based on problem-solving. This quest led me to look for resources and share my love of math at conferences – sparking my professional development/training itch.

DG5 Groupies!

My search for visualization and hands-on resources led me to a closet in our math department, where I found Discovering Geometry and Sketchpad. And as I used these resources to present at conferences, I got to know and LOVE Key Curriculum and become, I admit, a groupie. This led to getting to know the Key sales folks and being asked to become a Key consultant. All this PD experience led to an administrator job, where, miracle of miracle, all the Discovery books from Key were just being adopted, so I was part of this implementation, which led to meeting Key’s PD trainer, Tim Pope. As a result – lo and behold, this groupie is working for Key!

It was a dream come true! The Key family, one full of former math educators all trying to share the love of mathematics and create inquiry-based, engaging math through great problem-solving and dynamic math technology tools, was amazing. Then – the dream burst, the family split up, and the books went to Kendall Hunt (with Tim), and the technology to MHE (with me).

Heartbreak.

Casio Family

Time to open a new door: I decided to finish my doctorate and branch into the unknown world of education consulting. And that Key family? They are still there – sending connections and opportunities, which is why I now teach at Drexel, work with Casio, travel the world for The Dana Center and Department of Defense Education Activities, among many other experiences.

At this moment in time, my worlds have collided. My Casio family, which is a group of math educators trying to share the love of math and teaching and learning math through dynamic visualization, is inspirational. We’ve worked as a collaborative team, with Casio‘s incredible R&D team in Japan, to create a tool that is going to revolutionize mathematics. It’s everything math teachers want on one page, and it’s just in it’s baby-phase right now with potential for growth that is exciting.

The guys behind booth magic!

Classpad.net has a partnership with Kendall Hunt just recently announced. Those very Discovering Mathematics books I so love will be adding to their power of inquiry by providing our tool as the discovery math tool embedded in the ebooks. My new family is joining with my old family….(and Tim and I are reunited) (and we have a podcast too – 180days Podcast)(shameless plug)!

Right now? It feels like I’ve connected many parts of my life – where many of my previous ‘experiences’ and worlds have joined together. Not sure if this is the circle of life, or a Mobius strip, or maybe an example of a network with many nodes. But whatever it is, it feels right, it feels exciting and it feels limitless.