# 12/48 - 5/38 = ? Subtracting ordinary (common) fractions, online calculator, subtraction operation explained in detail. The answer, written in three ways. As a positive proper fraction (the numerator < the denominator). As a decimal number. As a percentage.

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## As a percentage: 12/48 - 5/38 ≈ 11.84%

#### How are the numbers being written on our website: comma ',' is used as a thousands separator; point '.' used as a decimal separator; numbers rounded off to max. 12 decimals (if the case). The set of the used symbols on our website: '/' the fraction bar; ÷ dividing; × multiplying; + plus (adding); - minus (subtracting); = equal; ≈ approximately equal.

 Add the fractions: 12/48 - 5/38 = ? Apr 01 19:59 UTC (GMT) Add the fractions: 2/7 - 1/9 = ? Apr 01 19:59 UTC (GMT) Add the fractions: 33/71,238 - 25/5,733 = ? Apr 01 19:59 UTC (GMT) Add the fractions: 101/6,200 + 78/9 = ? Apr 01 19:58 UTC (GMT) Add the fractions: 28 + 1/3 = ? Apr 01 19:58 UTC (GMT) All the operations with added fractions

## How to: Adding ordinary (simple, common) fractions. Steps.

There are two cases regarding the denominators when we add ordinary fractions:

• A. the fractions have like denominators;
• B. the fractions have unlike denominators.

### A. How to add ordinary fractions that have like denominators?

• Simply add the numerators of the fractions.
• The denominator of the resulting fraction will be the common denominator of the fractions.
• Reduce the resulting fraction.

### An example of adding ordinary fractions that have like denominators, with explanations

• #### 3/18 + 4/18 + 5/18 = (3 + 4 + 5)/18 = 12/18;

• We simply added the numerators of the fractions: 3 + 4 + 5 = 12;
• The denominator of the resulting fraction is: 18;

### B. To add fractions with different denominators (unlike denominators), build up the fractions to the same denominator. How is it done?

• #### 1. Reduce the fractions to the lowest terms (simplifying).

• Factor the numerator and the denominator of each fraction down to prime factors (prime factorization).
• #### Factor numbers online down to their prime factors.

• Calculate GCF, the greatest common factor (also called GCD, greatest common divisor, HCF, greatest common factor) of each fraction's numerator and denominator.
• GCF is the product of all the unique common prime factors of the numerator and the denominator, taken by the lowest exponents.
• #### Calculate online the greatest common factor, GCF.

• Divide the numerator and the denominator of each fraction by their greatest common factor, GCF - after this operation the fraction is reduced to its lowest terms equivalent.

• #### 2. Calculate the least common multiple, LCM, of all the fractions' new denominators:

• LCM is going to be the common denominator of the added fractions.
• Factor all the new denominators of the reduced fractions (run the prime factorization).
• The least common multiple, LCM, is the product of all the unique prime factors of the denominators, taken by the largest exponents.

• #### 3. Calculate each fraction's expanding number:

• The expanding number is the non-zero number that will be used to multiply both the numerator and the denominator of each fraction, in order to build all the fractions up to the same common denominator.
• Divide the least common multiple, LCM, calculated above, by each fraction's denominator, in order to calculate each fraction's expanding number.
• #### 4. Expand each fraction:

• Multiply each fraction's both numerator and denominator by expanding number.
• At this point, fractions are built up to the same denominator.
• #### 5. Add the fractions:

• In order to add all the fractions simply add all the fractions' numerators.
• The end fraction will have as a denominator the least common multiple, LCM, calculated above.