Finding Function Intersections – Casio fx-9860GII vs. TI-84 Plus: Casio IS Easier!

I admit to being a TI-83/84 user for all of my teaching.  Not because I had a personal preference for a TI, but because it was what all the schools where I taught in Virginia provided and recommended. It was in our books, it was what our state tests recommended, it’s what we were told to tell students to buy. Why? Was TI better than a Casio or an HP or any other brand for that matter? No. It wasn’t…and isn’t to this day. But – TI knew how to play the market and basically embedded themselves with publishers, testing companies, schools, to the point where today, schools & teachers & publishers are convinced TI is the better calculator option. Or maybe I should say they think it is the only option.

It’s not. It’s an option. But it’s not the better option in terms of cost and in terms of ease-of-use. In my 25 years of using TI, I can honestly say I still forget how to do most operations because there are so many steps involved or I can’t remember where the menu item lives. Obviously, as the Casio Brand Ambassador, I have a definite bias in my current opinion about hand-held calculators. However, it wasn’t my opinion until about 7 years ago, when Casio approached me, in my role as Director of PD/Education Outreach at Key Curriculum, to get some advice and suggestions for quality trainers who could help support Casio PD efforts. That’s when, for the first time, I actually used a Casio calculator and realized it was really easy and quick to learn – and I could remember things!!  All the Casio PD teachers,  many who were also Key trainers and who teach in classrooms all over the country to this day, were former TI users as well. But, once they tried Casio, never looked back and encourage others to make the switch as well. In my new role, I’ve been asking these teachers why, and the first answer I always get is “it’s so much easier for the kids to use and they remember how to use it”. The second answer I always get is “they are much better calculators in what they can do”.

In European countries, Casio has a much bigger share of the market than TI – they know about quality and ease of use. Here in the U.S. we are fighting the TI machine…it’s so embedded in our math culture and it’s hard to change, as are most things in education (think Common Core!) As Terry Walsh said in his NCTM session in Atlantic City, something a college professor told him, Casio calculators are much more user friendly, but TI calculators are more user familiar”. Sticking with the familiar and avoiding change is a disservice to our students, who deserve technology tools that are affordable and intuitive to use.

I thought it would be a fun idea, since Casio is always saying how much easier it is to use a Casio vs. a TI calculator, to actually show how. I picked two comparable graphing calculators: The Casio fx-9860GII SD ($79.99) and the TI-84 Plus ($139.00) to do a side-by-side comparison of a relatively common algebraic skill – finding the intersection of two functions. (Note: This is NOT a lesson on teaching this algebraic concept, so please, please, do not think this is how I would help students understand how to find the intersections or what those intersections represent in real-world context. There is a whole lot of discovery, hands-on learning, conversations, etc. that would occur if this were an actual lesson). What this video demonstrates is a step-by-step “how do you find the intersection of two functions using each graphing calculator” – nothing more, nothing less. The point being to actually demonstrate, talk-the-talk, walk-the-walk, and show ONE example of how a Casio graphing calculator is easier to use than a TI graphing calculator.

Watch the video: Step-by-Step Casio vs. TI Graphing Calculator