The most popular graphing calculator model line ever, the TI84 Plus, has continued to evolve into 2016. Barely one year after the TI84 Plus C brought color to the 84 family, Texas Instruments rebooted the color line with the all new TI84 Plus CE. The new 84 is new hardware with a new look, but much in common with its predecessor. So how does this new model stack up? Let’s take a look.
Actually, a lot has stayed exactly the same between the TI84 Plus CE and older 84 models, specifically the 84 C. If you have owned an older TI84 or need to get help from a tutor, sibling, or teacher that is used to working with the TI84 family, they will be able to jump right in on this model with no problems. The arrangement of physical buttons is the same, the menu system is virtually identical, and the you get the same great color screen that the TI84 Plus C had.
Truthfully, the biggest selling point for the TI84 Plus CE is for long time users to pick up a familiar calculator and jump right in with a familiar interface, but getting to do so with 2015 hardware.
The biggest change you’re going to notice with this model is the size. Officially, Texas Instruments says it is 30% lighter and slimmer than previous generations of the TI84 Plus. However, I can tell you that the difference when you hold it in your hand feels even more significant. I’ve been calling it the “TI84 Air.” The CE is the right size and weight to stuff into a book bag or purse without feeling like you are being burdened down by it. I’m a long time user of the TINspire family as well, and it felt to me like the TI84 Plus CE was even lighter than my TINspire CX. To be sure, I threw it on my kitchen scale. Sure enough, it weighed in at 7.0 oz. My TINspire CX was 10.0 oz.
While the physical location of buttons is identical to that of older TI84 models, the buttons themselves are smaller and rectangles, rather than rounded. This looks more like the TINspire buttons and gives the CE buttons a modern look.
The CE has its own new operating system. While it is nearly identical to previous TI84 models, an important difference is that you can’t transfer apps from older models to a CE. To remedy this, Texas Instruments is issuing new versions of all its most popular apps via their website. In fact, my CE review unit shipped with many popular apps like Finance, Conics, PlySmlt2, and Transfrm. Looking at the official TI app website for the TI84 Plus CE, the CE already has a couple of extra apps that the TI84 Plus C hasn’t received.
Comparing the TI84 Plus C to the TI84 Plus CE, you’ll be hard pressed to find many changes. I explored various menus, apps, etc. and noticed only a few extremely minor differences. For example, when exploring the “MODE” menu, a couple of options have changed. Here you can select what language localization you want if you are not a native English speaker, as opposed to going through apps. Additionally, while the 84 Plus C gives 3 options for the format of answers: “AUTO”, “DEC” (decimal), and “FRACAPPROX”, the last option is eliminated for the CE. I’m not sure what the rationale is here, but it means you cannot select a mode that automatically converts all answer from decimals back to fractions with the CE.
Additionally, there are a few visual tweaks with the PlySmlt2 app that I like. Rather than enter coefficients in a matrix for a system or list below the equation for a polynomial, the app now allows students to enter the coefficients right next to the variables. I think this will really help them understand what the app is doing. PlySmlt2 has always been one of my favorite apps for the TI84 family, and this is a small but thoughtful touch that shows TI is still thinking about how students use these apps.
The TI84 Plus CE has a “deep sleep” mode that allows it to hibernate while preserving battery if it’s not used for several days at a time. With regular use, it can run a month on a single charge, but in deep sleep mode, it can maintain nearly a full charge over summer break. I can tell you from personal experience that it really can maintain a charge for this length of time.
Additionally, Texas Instruments took a page out of another update they recently made to the TINspire line of calculators. Older TINspire CX calculators and the TI84 Plus C all had batteries that had a wired connection. The new Nspire CX and the TI84 Plus CE does not use this wiring, but instead just uses the sort of contacts you’d find in a cell phone with a removable battery. As a person who has had to remove the battery from literally hundreds of student Nspire CX’s, let me tell you that TI84 Plus CE users will appreciate this new battery design if they ever find they need to replace their battery. Replacing the old wired battery was a bit harrowing for the uninitiated, as it often felt like you might damage the calculator or battery during the replacement process.
Texas Instruments has definitely picked up on the fact that color sells and even has a website designed to help you pick your ideal TI84 Plus CE color. The CE comes in red, pink, plum, black, gray, and 2 shades of blue. The preview model Texas Instruments provided me with is gray, which looks a lot like the older TI84 Plus Silver Edition.
Both of the blue models look particularly enticing to me, but I can see the appeal to any one of these models. Don’t be surprised if some of these colors are in short supply if you look for yours during back to school shopping season.
While the TI84 Plus CE is a substantial upgrade to the 84 Plus C, there are a couple of minor issues I didn’t care for. The first was the changed location of the USB port, from top to side. I know from experience that students sometimes use their calculators while charging them. It seems like it would be easier to hold the CE and continue working with it if the USB port was still on top.
The second was a bit of “light leak” that I experienced around the corners of the display. I’ve never experienced this on any of the color TI models before including the 84 Plus C or the Nspire CX. I asked TI about this. They had an engineering team investigate it and reported back that they were confident it was because my review unit was a preproduction model. It’s a fairly minor irritation and very uncharacteristic of a TI product, but I feel obligated to point it out.
Since the TI84 Plus CE was released in 2015, a new version of the operating system, version 5.1 was released. As of 2016, the most uptodate version is 5.1.5, released January 2016. This was a minor operating system update in terms of features, adding a leading zero for decimal numbers. However, it includes bug fixes and performance improvement, and new operating system releases signal that Texas Instruments is committed to continuing to support this calculator going forward, which is important if you intend to make this your graphing calculator for 4 years of high school or college.
If you’ve made it this far in the article, I’ll assume you are a buyer that is serious about the TI84 family rather than the TINspire (review) family, which is the other serious contender from TI and still my favorite, despite the fact that I’m seriously impressed with the new CE. With Texas Instruments discontinuing the TI84 Plus Silver Edition and the TI84 Plus C Silver Edition, buyers will soon have just two choices in the TI84 family:
Lets briefly compare the TI84 Plus CE vs. TI84 Plus. Prices fluctuate, but typically there is a $20$25 difference between these models. There is no question that I’d pay that little bit extra to get the TI84 Plus CE as the CE makes the gap between color and black & white models even wider than it was with the TI84 Plus C.
If you can afford it, pick up a TI84 Plus CE on Amazon and don’t look back. It’s the best TI84 yet in a family of calculators that is widely known, understood, and loved by students and teachers alike and worth the extra few bucks. If you really can’t afford the upgrade, an alternative is getting a used TI84 Plus on eBay (they are built like tanks and last a really long time).
Click here to get the TI84 Plus CE with FREE shipping on Amazon. A small percentage of your purchase will support my work at Tech Powered Math. Thanks for your support.
]]>Please buy your TINspire CX on Amazon for the best price and FREE shipping.
Over my many years teaching in the high school math classroom, I spent more time working with the TINspire than any other calculator, and it has become my favorite graphing calculator platform. I like to keep the my TINspire CX review fresh, and since the last time I wrote this review, a new version of the operating system was released. So it seems only logical that a 2016 update of my review is also in order. This post is both a TINspire CX review and TINspire CX CAS review, although you’ll see while reading it, the two models have more in common than they do differences.
First, a seemingly minor but potentially important change for calculator buyer occurred last year when TINspire OS 4.0 was released for the TINspire CX and TINspire CX CAS. For the first time ever, the older “grayscale” (noncolor screen) models did not receive the operating system upgrade, meaning they continue to be stuck at OS 3.9. While 4.0 was mostly full of incremental upgrades (more on that later), if you are planning on buying your Nspire for up to 4 years of high school or college, I would hesitate to pick up an older model that might not continue to receive more upgrades like the “CX” model. Over that length of time, there could be enough changes to the operating system that the color models menu systems and features might start to look noticeably different from the greyscale models. I can tell you that 4 years ago, these calculators did look significantly different. I point this out because it is very tempting to look on Amazon and see that the TINspire nonCX models are still being sold there are and significantly cheaper. Proceed if you will, but buyer beware.
That caveat issued, I will say that the TINspire continues to be the most complete platform for students and teachers of mathematics at the high school and early undergraduate level. Several years ago, we saw the release of the TINspire iPad app (review). I was very impressed with this app and do recommend it even at close to $30. However, you should keep in mind that it’s simply not a replacement for a TINspire CX handheld since it’s not allowed on standardized tests like the SAT or ACT.
I will say that even before the updates of the last couple of years, I had felt that from an educational standpoint, the TINspire operating system was superior to any other TI product (such as the TI84 or TI89). I like the fact that it uses the type of interface that kids who have grown up in the internet era are familiar with. That means it has drop down menus, the ability to open multiple tabs like a browser, a drag and drop interface, and a file and folder system that’s just like using a computer. Graphing calculations have been much simpler, not requiring much button pressing beyond the trace feature because the Nspire automatically detects max and min values and intercepts while using trace. It’s also easy to type in your calculations using mathematical symbols so that they appear just like a student would see them in a book or write them in their homework, so there’s pretty much no code to learn. What really sets the Nspire apart has always been its dynamic properties. On one screen, you could have a graph, an equation, and a table of values. Grab the graph and drag it into a different shape, and all three adjust simultaneously.
Ever since the OS 3.2 update a few years back, Texas Instruments gave teachers and students the features that they have been asking for. There are some really awesome new features for the TINspire CX. The biggest upgrades with OS 3.2 were graphing features. Owners of any uptodate Nspire now have the ability to graphing conic sections and any equation written in “x=” form. This is something Texas Instruments users have wanted for years. You can see this and more below in the TINspire CX video review I recently put together.
The more recent operating system updates have been more modest in nature, but have definitely been noticeable and welcomed by regular users. For example, the most recent version of the OS, 2015’s 4.0 upgrade, primarily made incremental upgrades to graphing and geometry capabilities such as the ability to customize the 3D environment to show 3D graphs in either orthographic projection or perspective view and the ability to have geometric shapes have their points automatically labeled and their angles forced to integer values (see screen capture, right).
In addition to software upgrades, Texas Instruments has made some minor hardware upgrades as well. Since 2014, the latest TINspire CX model has had an improved battery design. Previously, if you were having battery issues with your TINspire CX, the battery was wired into the Nspire, and there was always a “hold your breath” moment of disconnecting that wire. The new battery is smaller and connected by a compression contacts like a cell phone battery. It pops in and out very easily. This isn’t an issue that comes up very often since the CX has a rechargeable battery, but I’m still glad to see it addressed.
Texas Instruments continues to be extremely active in teaching teachers how to teach with their TINspire platform as well. “Get Nspired” is more than a catch phrase. They hold webinars demonstrating engaging ways to use the Nspire CX that are of extremely high quality. Additionally, the last couple of years, they’ve started a series of initiatives STEM Behind Hollywood, STEM Behind Health, mISSion imaginaTIon, partnerships with powerful groups like the entertainment industry and NASA to show students how mathematics and science can be applied in exciting fields, all of course, with your TINspire graphing calculator.
So that’s what’s happening with the TINspire platform lately, but what made the TINspire CX such a hit in the first place? The TINspire CX will always be known as Texas Instruments’ first color graphing calculator, and an improved design came with it. When first released, it was a much thinner, lighter design that we’ve seen from TI in the past–more like the thickness of a standard scientific calculator than previous graphing calculators. The odd “wings” of previous TINspire models are gone. The screen is gorgeous. The resolution is good, the colors are bright, and the display is easy to read. You won’t mistake it for an iPhone, but it’s better than any display I’ve ever seen on a graphing calculator, including the Casio Prizm (review), despite my love for the Prizm. As I type this, the backlighting is bright enough to read easily from my deck in the shade, although not in direct sunlight. However, I don’t know anyone who would uses their graphing calculator in direct sunlight.
I’ve tried the image features on both the TINspire CX models and the TINspire graycale. You have the capability to load any JPG, BMP, or PNG file onto the device and graph functions right on top. It certainly works on both color and grayscale models; I’ve even posted pictures of the grayscale pictures on the Nspire already. However, I think the screen captures are a little deceiving. While the pictures look great on the computer screen in both color and grayscale, in some cases they’re actually kind of hard to make out the the Nspire grayscale. No worries if you are on a TINspire CX; images look great on the handheld.
I can also tell you that the buttons are “snappier” and more responsive than previous TINspire models. Back when I first asked him about this, Dale Philbrick, Texas Instruments Marketing Segment Manager for Mathematics, told me that this was accomplished by a combination of hardware and software upgrades.
Along with this change, there are no more interchangeable keypads. That means you can’t use the TINspire CX as a TI84 like older Nspire models. When Philbrick and I talked about this back at the time of the Nspire CX release, he said, “We felt like it was time for people to start using the Nspire as an Nspire.” No argument here. In the early Nspire days, I used to be frustrated with the occasional student who refuses to give up their Nspire’s TI84 keypad but then makes mistakes on problems that are so much easier with the Nspire, such as secant, cosecant, and cotangent (which can’t be found directly on the TI84). With each new TINspire OS, the TI84 just feels more and more outdated.
Judging based on polls I’ve run in the past on Tech Powered Math, I’ve found that there’s actually more interest among TPM readers in the TINspire CX CAS than there is in the TINspire CX. If you’re unaware of what a CAS calculator is, it is a Computer Algebra System calculator. This means the calculator has the ability to do algebraic manipulations on variables, such as x + x = 2x. This is a great thing if you plan to take the SAT or AP Calculus, where this type of calculator is encouraged, but not so great if you are taking the ACT, where it is banned.
The TINspire CX and TINspire CX CAS have most of their hardware and functions in common. They’re so similar, it’d be easy to mistake one for the other, even after playing with it for a bit. However, the CAS version has a number of menus and submenus tucked away that you won’t find in the nonCAS version. In the past, the questions I’ve received about the Nspire CAS tend to be from TI89 users wary of the the advanced calculus capabilities of the Nspire CAS. Since OS 3.0, differential equations and a host of advanced calculus features have been included for all TINspire models.
While I’ve taken math courses all the way to a graduate level, my teaching experience only goes through second semester college calculus, so I can really only speak to classes at that level and below. In those classes, I’d much prefer the TINspire CX CAS to a TI89 Titanium. Even though the TI89 Titanium (review) is an excellent calculator, the Nspire CX CAS is easier to work with on conics, has a much nicer UI, is easier for graphing, and has 3D graphing for a couple years now, a drawback that was a problem when the series was first launched, but no more.
If you find that you need a little help learning how to use your TINspire, I recently started a line of books designed to help students and teachers learn how to use the calculator. TINspire Tutorials Volume 1 is the TINspire for Beginners, that helps you navigate all of the basic features of the calculator. TINspire Tutorials Volume 2 is Using CAS Features Like a Champion, and will get CAS users started with those features only found on the CAS. Both books are currently available in Kindle format for the iPad, iPhone, Android, PC, and Mac.
At around $130, the TINspire CX and TINspire CX CAS not the cheapest graphing calculators available today, but they are well worth the price. When Texas Instruments debuted the TINspire line a few years ago, it had a few warts, but with each year, they’ve continued to make massive improvements to both the hardware and software. Even at the beginning, I was impressed with how much faster kids caught on to features like fractions, graphing, and tables on the TINspire than they did on the TI84. From remedial Algebra through AP Calculus and my 2012 Illinois state championship math team, the TINspire CX is my top choice for my students.
With the Nspire series, my students spent less time learning calculator code and more time learning math. Since the release of the TINspire CX and continued OS upgrades, this is a fully mature platform. No longer can Texas Instruments users cling to the good old days of the TI84 and TI89 and feel like they honestly have the best the market has to offer. The future has arrived. The TINspire CX is TI’s platform of the next decade.
Please buy your TINspire CX on Amazon for the best price and FREE shipping. If you buy through this link, a small percentage of your purchase will help support my work at Tech Powered Math. Thanks for your support.
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SAT Date 
RegisterBy Date 
Late Registration 
Jan 23, 2016  Dec 28, 2015  Jan 8 / Jan 12, 2016 
Mar 5, 2016 
Feb 5, 2016 
Feb 19 / Feb 23, 2016 
May 7, 2016 
Apr 8, 2016 
Apr 22 / Apr 26, 2016

Jun 4, 2016 
May 5, 2016 
May 20 / May 25, 2016 
You may also want to check out my interactive map of SAT results.
]]>Test Date  Registration Deadline  (Late Fee Required) 

September 12, 2015  August 7, 2015  August 8–21, 2015 
October 24, 2015  September 18, 2015  September 19–October 2, 2015 
December 12, 2015  November 6, 2015  November 7–20, 2015 
February 6, 2016*  January 8, 2016  January 9–15, 2016 
April 9, 2016  March 4, 2016  March 5–18, 2016 
June 11, 2016  May 6, 2016  May 7–20, 2016 
*This test date not available in New York State.
You may also want to check out my interactive map of ACT results.
]]>The above map can be used to explore ACT scores by state from 20042015 for all 50 US states across all subscores, composite scores, as well as percentage of students tested in a given state. Similar data is available for SAT scores by state from 20112014. I will add more data as it becomes available. The plot is hoverable, zoomable, and scrollable. You can also save any plot you create during your exploration as a .png file. If you enjoy this plot, please share it with others on Facebook, Twitter, or your social media platform of choice. You can also sort through the complete state by state scores for the SAT or ACT by clicking on the table tab.
Parents, please click here to check out Kaplan’s ACT/SAT test prep options, available at many different price points, guaranteed to increase your child’s score or your money back. If you follow this link, a small percentage of your purchase will support my work at Tech Powered Math. Thanks for your support!
]]>From course one to course two, the most visible change was the primary face of the class. That is, Emily Fox took the lead in front of the camera throughout Machine Learning: Regression, while Carlos Guestrin took a step back. Fox is very patient in her teaching style, never rushing to make a point, and giving you time to absorb information before moving on. I appreciate how she both uses concrete examples as well as works out the linear algebra as appropriate.
A variety of regression techniques are covered throughout the course, beginning at the beginning with simple linear regression, while progressing towards multiple regression, ridge regression, lasso, knearest neighbors regression, and kernel regression. Along the way, measures for assessing performance such as RSS and cross validation are explained as well.
Unlike the survey course (course one), in Machine Learning: Regression, students have the chance to implement these techniques as well as use preimplemented versions. I found that I came away understanding each of these algorithms much better than I did going into the course as a result of having to do these implementations myself, although there still were one or two (specifically I’m thinking lasso), where I was pretty reliant on the hints and starter code provided for building the actual implementation of the algorithm.
Once again, this entire specialization is conducted in Python, and Jupyter (iPython) notebooks are used throughout. I find that having a lot of structure with starter code is a blessing and a curse. It does keep you from getting too far off track, but there is also the reality that with less ability to wander, you may not learn certain things as well. For the most part, I think Guestrin and Fox walk this fine line pretty well.
As in course one, Graphlab from Guestrin’s company Dato was used throughout. To their credit, this time the instructors made it easier to do the work with other modules such as Pandas and SciKit Learn by making the data available in nonGraphlab formats from day one. I saw posts on the class forums that indicated there were students doing the work with other tools, but from perspective, since the notebooks were already written to leverage Graphlab, I really didn’t want to reinvent the wheel and stuck with that. This was less of an issue in the assignments that required students to implement a machine learning algorithm, since those assignments were light on Graphlab, and heavy on Numpy anyway.
I said in my review of the first course in this specialization that I was definitely going to stick around for another course to see what I got out of it. At this point, I’m in for the duration. These courses are a nice mix of techniques and tools that I already have familiarity with and those that I’m less experienced with. The teaching style is great, and I’m finding that even when techniques are covered that I’m already familiar with, it’s far from a waste of my time. I come away with a better understanding both of the theoretical underpinnings and applications of the machine learning techniques being addressed.
]]>Today, Texas Instruments announced a new partnership with NASA for STEM education that they are calling mISSion imaginaTIon. The new initiative launched with an online quiz about manned space missions, and there will soon be TINspire activities with mISSion imaginaTIon. A year long STEM design challenge encourages students to work on four spacerelated challenges, and the winner will receive a video chat with a NASA expert and a TINspire CX graphing calculator.
“Imagination is the fuel that feeds progress and innovation,” said Peter Balyta, Ph.D., president of TI Education Technology. “Alongside NASA, we are excited to unleash student creativity as students explore how science, technology, engineering and math can solve future problems on earth, in space and beyond.”
It is a great benefit to teachers that use Texas Instruments products in their classrooms that TI continues to develop engaging classroom curriculum such as STEM Behind Hollywood, STEM Behind Health, and now mISSion imaginaTIon. If you are interested in staying current on mISSion imaginaTIon, you can sign up for more information at the official website for updates, or follow its hashtag on Twitter, #mISSionImaginaTIon.
]]>I’ve included the code in two iPython Notebooks. The first collects retrieves the data in a couple of stages from Twitter. Simply put, collect Tweets from a community of users with an identifying characteristic (in this case, a chat hashtag they all use). Then, collect all of the friends of those users in order to find relationships between them.
The second notebook is creates a nice interactive visualization of the data collected from the first notebook using Plotly. Of course, depending on your use case, Plotly may not be the best tool. Gephi may be far better for quick and easy analysis from your local machine. However, I wanted to do an example that I could share on the web.
I also envisioned the possibility of high school teachers reproducing this experiment with their students. Directing students to a Plotly page that had been prerendered is certainly easier than installing Gephi on many machines in a lab if your district IT person is not cooperative, which is the case in some school districts.
]]>I taught graph theory myself for several years as part of a discrete mathematics course. While the textbook I used included many examples of “real world” problems that I found engaging, the students didn’t always agree. With an enthusiastic teacher and cooperative school, there is no reason that the experiment I did with #EdTechChat couldn’t be used to create a Twitter social graph of the students in a class or, better yet, a school. Seeing themselves, their classmates, and possibly teachers as a part of a Twitter graph is an engaging data set to explore.
Let me briefly describe the methodology for creating such a graph without the programming details. The Twitter API (Application Programming Interface), which is how Twitter allows the public to access their data via a programming interface, is used to search the Twitter timeline for a specific search term. In this case, I searched for #EdTechChat. In the case of a school, one could create a unique hashtag, say #MHSTwitterExperiment. All the usernames were pulled for the people that used that hashtag over a specific period of time. Then, again using the Twitter API, a search was done to see who those users follow, eventually restricting those results to only other users that had participated in the #EdTechChat.
From there, a visualization was created with Plotly that allowed viewers to interact with the data. I used followers and following, but of course, teachers of graph theory know that these are really proxies for indegree and outdegree. Betweenness centrality was also used to color the nodes as a rank of influence. Centrality wasn’t a term I used with my students when I taught graph theory, but it has become increasingly of interest in the field and is something beginning students of graph theory can understand.
Of course, there’s no reason that Plotly is a requirement for creating a visualization. In fact, teachers that have the ability to install free software can use Gephi and will have more options as to how they display and analyze the data gathered from the Twitter API.
The only catch with this whole process is that you do need to get the entire community to tweet the same hashtag at reasonably close to the same time unless you have another way to identify them. Having taught in the public school system for over a decade, I know that an enthusiastic teacher can definitely get kids on board with this kind of thing, but I am also realistic about potential obstacles (parents, administrators, skeptical colleagues).
All of the code to complete this task is readily available via my GitHub account, so really there’s no need for me if any codesavvy teachers decide to run with this. However, if there’s anyone out there that thinks this sounds exciting but feels like certain aspects of it sound intimidating, I would welcome the opportunity to lend a hand. Having been out of the classroom for a year now, I’m hoping to occasionally find some opportunities to make my new career and previous career intersect.
]]>If you hover over a node, you’ll get information about it: the username, the number of followers and following (these counts refer only to the community of users that took part in this chat, so followers and “followees” that didn’t participate are excluded), and the betweenness centrality. That last number is a measure of the number of shortest paths in the graph that pass through a particular user. It is one possible way to measure the influence of a user within this community. Some of the most influential users in this community as measured by betweenness centrality include @teachintechgal, @KleinErin, @thomascmurray, and @EdSurge. Don’t miss out on the fact that this interactive plot allows you to zoom in and out as well on different regions of the graph.
I feel the methodology employed to generate this graph could be of interest to others. As such, I am publishing it to my GitHub account and have a couple more blog posts on this topic. In particular, I would love to find a school interested in using this method to give students an opportunity to do a graph theory exploration that would go beyond what they’d normally get from a textbook.
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