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Math K-Plus

How To Add Fractions With Common Denominators And Unlike Denominators

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Learn Fraction Addition With Common Denominators Or Unlike Denominators





The simplest fraction math problem is addition of fractions with the same denominator. It is a three step procedure to get the final answer:
  • Add the whole number part of all fractions to get the sum.
  • Since all the fractions have the same denominator, add all fraction numerators to get the sum of the fractions.
  • Simplify the fractional sum and combine their result with the whole number sum.
  • You are now ready to practice Adding Fractions using our smart calculator. Try these examples: 1/6 + 4/6 , (here is a difficult one) -5 5/8 + 2 2/8 =

Add Fractions With Common Denominators (Example)


59  +  89  = 


The Denominators Of Both Fractions Are The Same - Add Numerators (5 + 8)

(5 + 8)9  =  139  = 



Converting Improper Fraction To Mixed Number

139  =  149




The alternative fraction addition problem is adding fractions with unlike denominator. It is a three step procedure to get the final answer:
  • Add the whole number part of all fractions to get the sum.
  • Since some or all the fractions have different denominators, we must convert all fractions to have the same denominator before they can be added together. This conversion is done by cross-multipying two fractions at a time to get common denominators; note when we cross-multipy, we are multiplying the fraction by the value one (1) e.g. 6/6 so the true value of the fraction is not changed. Once the denominator of all fractions are the same, add the numerators.
  • Simplify the fractional sum and combine this result with the whole number sum for the final answer.
  • You are now ready to practice Adding Fractions using our smart calculator. Try these examples: 1/2 + 4/6 , (here is a difficult one) 3 1/8 + 2 6/4 =

Add Fractions With Different Denominators


38  +  56  = 


We Must Cross-Multiply Both Fractions To Get A Common Denominator

38  =  3 × 68 × 6  =  1848

56  =  5 × 86 × 8  =  4048


Both Fractions Now Have Common Denominators - Add Numerators (18 + 40)

(18 + 40)48  =  5848  = 

Greatest Common Divisor
5848  =  58 ÷ 248 ÷ 2  =  2924  = 

Converting Improper Fraction To Mixed Number
2924  =  1 524





Recommended reading: Adding Fractions Calculator, How To Subtract Fractions, How To Multiply Fractions, and How To Divide Fractions.