the history "highlighted" part should be more in contrast with background...chose something like gray

When selecting a number value in the converter view, the selection range is automatically extended to include the unit designator, which makes copy/pasting the value into the calculator view more difficult than it needs to be.

I suggest not auto-extending the selection, allowing the user to only select the numerical portion of the result.

i^2=-1 + 1.224646798818428e-16i the answer suppose to be -1
so why the extra term?

Unit names, like Angstrom, are long and are likely to be accompanied by a long number, especially if not using scientific notation, since the unit size is so small. Converting even a small number like 1 cm to Angstroms results in a large number that is truncated. League is another kind of long name. Not sure what the abbreviation is for that.

Like the GCF of 9t and 15m

I would like to use Numerics also on my Android phone. Are you planning Numerics app in Google Play ?

like where u can add up bills then save for a later date

enter in A, B, and C values and have the calculator substitute them into the equation

only square and no other root can be calculated

% button after all it is 2013 lol

Converting for Cooking; spoons to tablespoons, cups to Tbsp & tsp etc. Or if you wish to make your calculator more valuable, then add specific info like; convert cup of butter to weights of metric and or pounds. and same for all ingredients which available in many food calculators.

I would like there to be the ability to calculate polynomials.

Please add a tape function

8_>v+3
Solve the inequality for .

have a space for MY CONVERSIONS

have a conversion for GAUGE to THICKNESS in mm

the different colors for where the screen is green and the scientific calculator for those people who need the extra help

User of an calculator, normally enters a formula in one line.

It can be difficult to read the formula, if it's long. Therefore provide alternative view (like "scientific calculator", existing chrome extension).
Even better generate the alternavie view in realtime when the user is typing.

example

  1

1+ ----

  2