There’s a basic assumption that consumers have about calculators: that you put numbers in, and the calculator spits answers out. Correct answers. Accurate answers. In the case of the Texas Instruments scientific calculator that John bought recently, he tells Consumerist that this is a false assumption. As false as the answers it gave him for the area of a circle.

He writes:

Texas Instruments believes its new TI-36X PRO calculators are not defective for returning incorrect answers, and will not honor their warranty. Who would expect a calculator to actually calculate correctly? If the calculations are important they suggest using a different calculator to verify the results.

I bought the new TI-36X PRO in July at an office supply store, and in August while calculating the area of a circle I discovered the calculator was returning significant incorrect answers. Easy to miss, unless you’re really paying attention and know what your doing. Returning wasn’t an option, since I was past the 30 day return window.

In August, I contacted Texas Instruments at both, 1-800-TI-CARES & TI Tech support 972-917-8324. Both confirmed the error, and both sent a report up to the developers to fix. I was surprised that even though the calculator was defective, they would not honor the warranty. They wouldn’t send me a equivalent non-defective calculator or issue a refund. The representative I talked with said they will decide if they will have recall, but that it probably won’t happen until enough people call in to complain about the errors. I personally worry about the students getting dinged on homework and tests because of the calculation errors. Hopefully there are no NASA scientists using this calculator or any engineers whose calculations could put a life at risk.

I have since learned that this calculator was introduced in 2010 in Europe as the TI-30X PRO, and was recalled shortly after, for different calculation errors. They reintroduced it, and brought it to the US as the TI-36 PRO, but it still contains serious software bugs. The previous version the TI-30X IIS had a recall because of incorrect results also. See a pattern here?

In closing, I just wanted to put the word out to warn students/professionals to be beware of this defective calculator, and know that the Texas Instruments warranty is worthless.
Feel free to contact me anytime. Keep up the good work consumerist!

Students who bought shiny new calculators at the beginning of the school year, consider yourselves warned, and be sure to call Texas Instruments if you notice any errors. Your computer should have a scientific calculator as an application, and your smartphone also might have one. Call Texas Instruments yourself if you notice any discrepancies between calculators.

Or use this as an excuse for your poor math grades. But we recommend the “be warned and double-check your work” thing.

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