iMath
Add, subtract, solve complex formulas, figure out the tip for your bill simply and quickly, calculate the probability of ten million coin-flips all landing heads, convert from miles/hour into kilometers/second and from teaspons into liters: you can do it all quickly with iMath.

Just type something you would like to calculate in the box and hit the equal sign. Great on the go!

For example, try "sqrt(256)", "e^(pi*i)", or "18% of 45.23". Or, try converting units: "80 km/h in mi/h" or "2 lb in kg".