Best Graphing Calculators for Pre-Calculus & SAT/ACT

[DavidME]

My suggestion is, if you have the self-control, have a TI-89, as it will serve you well throughout your years. But you CANNOT solve problems with it: use it to check your work, or for questions that might require a graphing calculator or for 38.2*291.203, but it should otherwise NEVER be part of your first solution. It's a great tool to check, but it becomes a terrible crutch if abused.

This is good advice.

I would add that your first calculus class should teach you how to graph any function on paper without the help of a calculator. This is vital because later in your academic life you'll be confronted by equations that do not behave nicely with the resolution and "default fit" window sizes of the TI. You can get into a situation where looking at the graph of a function with 4 different step sizes or windows gives you four different graphs and you have no idea which is the correct one.

Another bad habit that dependence on any calculator can get you into is the "plug and chug" approach. It is usually always a good practice to solve equations algebraically with symbolic variables and only substitute values into the equation when you have it in the simplest form and hopefully solved explicitly for your unknown. Falling into the habit of immediately punching numbers into the TI when confronted with a problem will make life very hard on yourself. For very long problems you can also accumulate a round-off error that throws your answer off.

Also, in the case that you use it for "38.2*291.203" don't fall in love with the false precision of the calculator. If you have measurements that are precise to three significant figures, and perform some calculation with them, your TI might tell you that the answer is 11,123.9546. The answer is wrong because it says you know something to 9 significant figures of precision. The problem is that one of the measurements you answer relies upon is only accurate to three significant figures. Your answer is always limited by the significant figures of your measurements. In the case of "38.2*291.203" the answer is limited to three significant figures, or 11,100.

Don't worry too much about any of this right now. Chances are that at your level all the equations you will be given will behave nicely and your teachers don't care about significant figures or accumulated round-off error.

Just know that calculators are very good at crunching numbers but are very bad at thinking. You have to do that part. The students who use the TI's as a crutch so they don't have to think pay dearly for that attitude later in life.

 

[vaikunth2004]

I am taking the act and I want a good priced (not too expensive) calculator. What are some suggestions? I have TI34II and TI 30X.Both are ok relatively.(i don't use calculators much) I don't need one that graphs and all those special functions.HELP ME!

 

[qntty]

If you're looking for a calculator comparable to the TI-89, you should also consider the HP 50g. Both calculators have their advantages, but after researching them I decided to buy the 50g. There used to be a huge thread somewhere on PF debating which one is better. To me it seems like the 50g is a lot more customizable but has a harder learning curve. If you intend to use the calculator for several years (not just for a few calculus classes) then it might be worth it to learn how to use the 50g, but both are praised by their long time users as excellent calculators. If you're looking for the safe option, I'd go with the Ti-89 because its easy to learn and more popular so most teachers/other students will be able to help you.

Edit: just noticed that the OP started this thread in January, and that response was meant for him. For taking the ACT you don't even need a calculator at all (assuming the ACTs are just like the SATs). I wouldn't buy one for the ACTs unless the ones you have aren't capable of adding, subtracting, multiplying and dividing.