Calculator on Yahoo home page is inaccurate.

Nightowl

I have been using the calculator on the home page today. It gives wrong answers!!
When I subtract 10.78 from 130.01 I get 119.22999999999999. This is a big error in it's program and I found a few others to. The calculator could cost people money if they are working out bills and don't pay enough because of it.

I've sent them feedback but didn't know how to complain directly.

kwikbreaks

It's a pretty obvious rounding error though and when writing a cheque for £119.22999999999999 alarms bells would probably sound in most peoples minds.

You can get calculators in pound shops and Windows includes one too (with much more inventive bugs unless it has been patched).

The_Grandmaster

can't go wrong with a Casio calculator!

BillScarab

Or you can just type calculations into the Google search box and get thte result.

John_Gray

If you type 130.1-10.78= into the Google search box, like BillScarab says, you get:

130.1 - 10.78 = 119.32

More about calculator.

To understand why you get the sort of rounding error you describe, you really need to read up on floating point calculations.

And the way of testing any calculator to see if there is circuitry in it to do proper rounding is to enter
1 ÷ 7 x 7 =
The answer should, of course, be 1.000000
Cheap calculators will give something like 0.9999997

spud17

Or you could use the calculator, available in the OS, generally, start/programs/accessories/ calculator.
Use it in conjunction with the numeric keypad.

[Deleted User]

The_Grandmaster wrote: »

can't go wrong with a Casio calculator!

Or the trustworthy TI-83, I still use mine now..

BillScarab

spud17 wrote: »

Or you could use the calculator, available in the OS, generally, start/programs/accessories/ calculator.
Use it in conjunction with the numeric keypad.

I tend to use Google now if I only have a couple of calculations to do as I've always got a browser open so it's quicker than opening the calculator int he OS.

spud17

BillScarab wrote: »

I tend to use Google now if I only have a couple of calculations to do as I've always got a browser open so it's quicker than opening the calculator int he OS.

Fair enough, you're a regular here, so know what you want, but I wonder how many here don't even realise that their OS has a calculator, or even looked in accessories.

BTW, I claim the oldest working calculator, a Prinztronic sr99p from c.1971

Patrick20

I use the calculator that comes with windows. Its not necessarily slow to get out if you use it with a program like executor or launchy. I just press alt+spacebar then type calc, hit enter. They are really quick to open any program for that matter. I've got my matched betting spreadsheets all set to open on keywords.

tomstickland

Nightowl wrote: »

I have been using the calculator on the home page today. It gives wrong answers!!
When I subtract 10.78 from 130.01 I get 119.22999999999999. This is a big error

The correct answer is 119.23, so that's not a big error at all.
Actually, it's a tiny error, less than a part per million.