I made a video to illustrate the bug, embedded below:

To check if your TI-36X PRO has the bug, first make sure you are in MathPrint mode. You can check this by pressing \(mode\) and scrolling down to the bottom of the list of options. Now, you need to tell the calculator to display answers in mixed fraction form. To do this, type \(1.75\) into he command line, then press \(math\) then \(1\) then enter. You should see the result \(1\frac{3}{4}\). Then type \(\pi12.5^2\) into the command line. When you hit \(enter\), you should receive the answer \(490.8738521\). Now press the answer toggle button (it is directly above \(enter\)) and your calculator will display \(154\frac{\pi}{4}\) if your calculator has the bug. The mathematically correct answer would either be \(\pi154\frac{1}{4}\) or \(\frac{\pi654}{4}\). Remember to clear the memory (hit \(on\) and \(clear\) at the same time) after you try this!

Overall, I’m still a fan of the calculator. To avoid the bug, I never try to convert anything to a mixed fraction. There are very few times where I ever need a mixed fraction anyway. You can get all the information you need in either decimal or improper fraction form. I actually used this calculator on the Fundamentals of Engineering Exam and I was very happy with it.

LINKS:

TI-36 Wikipedia Page: http://en.wikipedia.org/wiki/TI-36#Programming_Errors

The Consumerist Article: http://consumerist.com/2011/09/this-texas-instruments-calculator-cant-calculate-correctly.html

Product Guidebook from TI: http://education.ti.com/downloads/guidebooks/scientific/36xPro/TI36PRO_Guidebook_EN.pdf

Here is a video from MrTechLabs describing the same problem:

The answer is not wrong on the calculator it is telling you 156+pi/4 still just as it did with 1.75=1+3/4. This is not a bug it is just a misconception

ReplyDeleteNo, 156+(pi/4)=156.785398... not 490.87385... which is the value we are trying to represent. The calculator's value is mathematically incorrect.

DeleteOkay, I'm a little confused. I just bought this calculator.. I did as you said to see if my calculator had the bug & the answer I got back was 156 π/4. Is this wrong? or right?

ReplyDelete@rachel wrong indeed..the real value should be 490.8.jst think tis way,for solving (12.5^2)*pi ( 12.5^2 will be more than 144+ approximately ,which is multiplied by pi whose value is more than 3 so the real ans should be more than 450+ ie 490.8) our calculator is giving 156 pi/4=156.78..i hope ur confusion is nw cleared

ReplyDeleteThe two correct answers should be pi*156-1/4 or (pi*625)/4

ReplyDeleteOh, I get the problem. The calculator knows the number to be (156 and a fourth) of pi, but it displays 156 and pi over 4.

ReplyDeleteMixed fractions are dumb anyway.

I just bought my TI36. I tried π12.5^2 and i got 154π/4. Then I hit ''on'' + ''clear''. Now after the memory cleared I'm getting 625π/4. Does it mean there is no more bug?

ReplyDeleteNo. The bug is still there. You just have to refresh the bug by using math 1 at any time.

DeleteI too have gotten rid of the bug by holding down [on] and [clear] at the same time. Thanks!

ReplyDelete"On+Clear" Seems to have cleared up the issue for me as well... Strange...

ReplyDelete