This article rounds up the best calculator apps available to download right now, from fairly streamlined calculators to apps that feature specialized functions for engineers and scientists.

Soulver has some basic trig functions, currency and unit conversion, and logical operators, and you can save your calculations to iCloud or Dropbox or send them as HTML-formatted emails.

Type or photograph a math problem to solve and see the steps to the solution. Supports arithmetic, algebra, inequalities, basic trigonometry, and graphing.

Most calculators default to degree mode, which can lead to incorrect results when evaluating trigonometric functions with radian inputs.

The iPhone's scientific calculator provides exponential, logarithmic and trigonometric functions. It even has some hidden functions that reveal themselves if you hit the button that reads ‘2nd'.

Everybody needs a calculator, and your options are virtually unlimited. Here are the best calculator apps for Android.