# How to fix my calculator?

Asked by Gooood (50) January 10th, 2010

Here’s an example. If I type in 0.30×10^-12 / 1.6×10^-19 = 1.875×10^-32

When the answer should be 1.875×10^-8.

I have to type in 0.30 / 1.6×10^-7 for it to give me the right answer why is it doing this?

Observing members: 0 Composing members: 0

Maybe it needs new batteries??

ccrow (8072)

type 0.30×10^-12 / 1.6 / 10^-19
or 0.30×10^-12 / ( 1.6×10^-19 )
or 0.3E-12 / 1.6E-19

After all, when you do 0.30×10^-12 / 1.6×10^-19 it is 0.30 times 10^-12 divide by 1.6 times 10^-19.

Hope that makes sense…

gagara (102)

@gagara
Thanks so much, it’s just me being silly.

Gooood (50)

Makes me glad that my HP-48G uses Reverse Polish Notation…

jerv (31027)

just a tip you can never use too many parentheses. they are a great way to make sure the calculator is doing what you want it to do. they may seem to be a little bit of a waist but they do work.

whothei0 (213)

@whothei0 I’ve been known to nest them 4–5 deep for some of the stuff I do. That way, you know operations will be performed in the correct order.

jerv (31027)

lol way too true especially in programs! there you NEED them. i have made that mistake before and never going to do that again.

whothei0 (213)

I have a program that you enter the rim size, tire width, and profile (to calculate the tire’s circumference) along with a couple of gear ratios and then you can figure out the car speed in MPH from the engine RPM or vice-versa. Try that without a lot of parenthesis!

jerv (31027)

wow that is crazy! the best i have i wrote one to solve a three variable problem it was over 18 lines. took forever to write it

whothei0 (213)

or