With the latest release (0.6) of the Online Scientific Calculator, come two new functions: INT (Integer) and GCD (Greatest Common Divisor). Here is a brief explanation of how they work and why they are useful.
Both new functions can be typed directly to the calculator input field and are also accessible from the two new keys on the bottom left of the calculator keyboard.
The INT function
The INT function, accessible from the calculator new ‘int’ key or by typing ‘int’ directly in the input field takes one argument and returns it’s integer portion. It doesn’t perform any rounding, instead it removes all numbers after the floating point. It is equivalent to the floor function found in many computer languages. It returns the largest integer that is not greater than it’s argument.
The GCD function
GCD stands for Greatest Common Divisor. It’s other names are Greatest Common Denominator and Highest Common Factor. It is a very important function for reducing fractions to it’s lowest terms. This function is used often by the online scientific calculator because every time a new fraction is entered or calculated, it is automatically reduced to it’s lowest terms. Although the function is used internally, I hadn’t planned to add it as a usable function of the calculator until I read a blog article by a math professor who put it in his wishlist for the ideal online calculator.
Also the gcd function is accessible from the virtual calculator keyboard. (Note to self: the keyboard is getting a bit too crowded. Maybe some future functions could be implemented but not be part of the keyboard and made accessible by some sort of menu. Any comment appreciated).
The GCD function currently takes only two arguments. To calculate the gcd of more than two numbers, you can call it recursively like this: gcd(15,gcd(30,gcd(95,5))).
Passing values other than integer to the GCD function will result in an error.
Although the calculator natively simplifies all fractions, the GCD function maybe useful to those students who are learning fractions arithmetic and want to verify their results.
Update: Alcula now features a new page at GCD calculator where you can calculate the global common divisor of up to 10 numbers.