As I’ve said before, math isn’t my strong suit. My calculator says
I assume this means 1135288 followed by 21 zeroes?
No, it means you take the decimal point in 1.135288 and move it to the right 21 spaces, resulting in 15 zeros (because there are already 6 digits after the decimal point).
No, it means there are 21 places after the decimal point. Some of them might be zeroes, but the first few at least are 135288 .
Expanded out in non-calculator notation, 1.135288e21 means “1.135288 times ten to the 21 power”. That’s a bit more than “1 times ten to the 21 power”, which would be 1 followed by 21 zeroes.
FWIW, that format is referred to as Scientific Notation, and it is used to handle very large (or small) numbers more easily. With large numbers you move the decimal point to the left and use an exponent to indicate how many moves you made. How many steps to the left you move often will depend on how many significant digits a number has, though I’m not sure that is taken into account with a calculator display.
This could be “Engineering Notation” instead. Engineering notation works like scientific notation except the number after the “e” is an integer multiple of 3, and the number with a decimal point can be #.#### or ##.### or ###.##. I think the intent is that this works like saying so many thousand or million or billion, using words that mean 10^3n where n is any integer.
Since 21 is evenly divisible by 3 and your number begins with digit dot digit digit digit, we can’t tell from this example.
Usually this is kind of a dumb point, because people don’t use engineering notation that often, and it’s a calculator feature because they’re trying to think of features they can cram in there. I point it out here because you might be trying to figure out how the calculator works and it’d be confusing to see that it is not set in scientific notation now, or it might not occur to you that “ENG” could be the mode setting if you are looking for “SCI” and something else such as “FIX” or whatever they call it on your calculator.
Totally didnt know that. Very cool! Thanks.
In my experience, engineers (or at least, college engineering students) do in fact tend to use engineering notation.
Slightly highjackish, but isn’t that why Angstroms went out of fashion in optics, and everybody uses nanometers instead? Angstroms are 10^-10, and that negative tenth power isn’t divisible by three, so, now, people use nm, 10^-9 (and, obviously, adjust the mantissa…)
(Jeepers, how long has it been since I’ve used the word mantissa!)
No, Angstrom units were dropped because they are not metric standard. There is nothing wrong with using them of course, nm is the SI standard.
And if you had encountered this number in print, or handwritten, it would have looked like 1.135288 x 10[sup]21[/sup] (maybe with a raised dot in place of the x to indicate multiplication), but most calculators display scientific notation either the way you wrote it, or by living a space between the 1.135288 and the 21.
Hell yes!
Now that you mention it, Mantissa would be quite an evocative name for a woman. Bond girlfriend? Bond enemy?
Isn’t there generally considerable overlap between these two?
If I had a nickel for every time I’d used the word mantissa, I’d have about twenty cents.
If I had a nickel every time someone used “mantissa” when they meant “significand”, I’d have way more than that.
i’d have just a fraction of that.
I see only one def online that mantissa is simply “the stuff after the dot.”
The precise sense, I gather, is that it should be called so only in the context of a statement about logarithms, so the above definition, for OP, is correct only when specifying (or assuming, as obviously we do here), that log 10 is afoot.
Right?
Zut? How are they different? The only place I looked (to check the spelling) implied they’re synonymous. (Yeah, had to look up the spelling on that, too… Sheesh, what a language!)