Java中的分数

Question

I don't know how to represent fractions. I'm supposed to add two fractions together based off of the numerators and denominators that the user inputs for both fractions. What the activity is asking me to do is have this as the printed outcome.

What is the numerator of the first fraction? 1

What is the denominator of the first fraction? 2

What is the numerator of the second fraction? 2

What is the denominator of the second fraction? 5

The sum of 1/2 + 2/5 = 9/10

The numbers after the questions can be changed based on user input.

Below you can see what I have written.

public class AddFractions extends ConsoleProgram
{
     public void run()
     {
         int numeratorFirst = readInt("What is the numerator of the first fraction?");
         int denominatorFirst = readInt("What is the denominator of the first fraction?");
         int numeratorSecond = readInt("What is the numerator of the second fraction?");
         int denominatorSecond = readInt("What is the denominator of the second fraction?");       
     }
}

Answer 1

You can add two fractions after you convert them to a common denominator. The easiest way to do this is:

1. Multiply the first numerator by the second denominator.
2. Multiply the second numerator by the first denominator.
3. Multiply the denominators together to get the common denominator.
4. Add the numerators.
5. Reduce the resulting fraction if necessary. (Check to see if the denominator is evenly divisible by the numerator, or vice-versa if the numerator is bigger.)

Answer 2

When adding fractions, you have to make sure they share a common denominator, then add the numerators. So, for 1/2 + 2/5, you would want to make sure they both have 10 as the denominator, representing them as 5/10 + 4/10, so you can then add the numerators and get 9/10.

Here's how you might want to do it in Java:

numeratorFirst = numeratorFirst * denominatorSecond;
numeratorSecond = numeratorSecond * denominatorFirst;
denominatorTotal = denominatorSecond * denominatorFirst;
numeratorTotal = numeratorFirst + numeratorSecond;