Okay so my apologies if the answer to this is blatantly obvious but I’ve never noticed this before and quite confused why my calculator is giving me the wrong # and thus the wrong answer. Here is the problem for example: Ke=D1/P0+g D1=2.5 P0=25 g=8% Here are my exact steps: [2.5][/][25][+][8][%key]…when I press the “%” key after [8] it is showing “0.008” and thus giving me an answer of 10.8% and not 18%. Have I been studying way to long and my brain is too fried to figure this out? Probably. But any suggestion as to why this is happening would be much appreciated. P.S. - It is also happening even if I put “( )” around the 8%.
and if you reset you calculator to zero, and then just press 8 %, do you still have that ?
You need to put parentheses around [25][+][8][%key]
WTF…That sucks…Try restoring your calculator to factory default and see if you still have that problem…btw, which calculator are you using?
I’m using the BA II Plus and have been using the % key forever and just realized it is doing thing… When I reset to 0 then press 8 then % then = it gives me .08 which is obviously correct. Im curious why its only doing this on a problem such as the one I mentioned above…
Well, now I know the answer for this. BA II is programmed to behave like this, for that matter any calculator, you can try it on any calculator. Although, I am not sure it these calculators will have a different behavior under different modes. However, in the standard mode, never ever try percentage after + or - sign in such calculations, you will never get the expected answer as calculator interpretation of percentage is different than yours. Here is how it works: Let’s say if you try 10+8%, BA II will interpret it as 10+10*8%, so answer will be 10.8 but you were expecting it to be 10.08. This works more like sales tax commission. Now if you try 100-25%, BA II will interpret it as 100-100*25%, so answer will be 75 but you were expecting it to be 99.75. This works more like income tax application. Here is the BA II manual, you can find explanation there too under “Math operation section”: http://education.ti.com/guidebooks/financial/baiiplus/BAIIPLUSGuidebook_EN.pdf
Here are some more details from manual, it has to do with the mode you have selected. If you are comfortable with chn mode, choose AOS, which is more intuitive to most people. Choosing Calculation Methods When you choose the chain (Chn) calculation method, the calculator solves problems in the order that you enter them. (Most financial calculators use Chn.) For example, when you enter 3 H 2 < 4 N, the Chn answer is 20 (3 + 2 = 5, 5 * 4 = 20). Using AOSé (algebraic operating system), the calculator solves problems according to the standard rules of algebraic hierarchy, computing multiplication and division operations before addition and subtraction operations. (Most scientific calculators use AOS.) For example, when you enter 3 H 2 < 4 N, the AOS answer is 11 (2 Q 4 = 8; 3 + 8 = 11).
A temporary solution to that problem could be reversing the sequense entered: Instead of entering Ke = D1/P0 + g (So it will be [2.5] [/] [25] [+] [8%]) You better enter Ke = g + D1/P0 (thus the new sequense will be [8%] [+] [2.5] [/] [25]) I think it may mess up the formula a little bit at first, but at least the answer will always be right
No you don’t have to change the sequence, rather change the mode in calculator if you are not comfortable or use brackets around percentage as Joey suggested. Reversing might be OK in this problem but think about a lengthier problem where you have percentage in between, you will either get it wrong or spend a lot of time on it.
Many thanks Sgupta and Firefox, i see why it happens now. I think to be on the safe side I will just manually type the percentage on test day --> .08 instead of [8][%] Many thanks!