Adding Mixed Numbers
Part of the Factors & Fractions section of Coddy's Pre-Algebra journey. Lesson 46 of 58.
To add two mixed numbers, add the wholes to the wholes and the fractions to the fractions. Take 3 and 2/3 plus 1 and 1/2. The wholes give 3 + 1, which is 4. The fractions give 2/3 + 1/2, which over a common denominator is 4/6 + 3/6, or 7/6. So the sum is 4 + 7/6.
This is allowed because a sum can be regrouped in any order. 3 and 2/3 plus 1 and 1/2 is just four numbers added, 3 + 2/3 + 1 + 1/2, so the wholes may meet first and the fractions after.
Notice that 7/6 is more than one whole: it is 1 1/6. A mixed number keeps its fraction part below 1, so carry that whole over to the 4: 4 + 1 + 1/6, and the sum is 5 1/6.
Challenge
Work out 2 3/4 + 1 1/2. Add the wholes and the fractions in your first line, then carry the extra whole and finish with a mixed number.
Try it yourself
Simplify the expression
This lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Factors & Fractions
1Factors and Multiples
What a Factor IsFactor PairsDivisibility RulesMultiplesPrime or CompositeRecap: Factors and Multiples4What a Fraction Is
Parts of a WholeFractions on the LineA Fraction of a NumberImproper FractionsRecap: What a Fraction Is7Multiplying Fractions
Top Times TopCancel FirstWhole Times FractionA Fraction of a FractionRecap: Multiplying Fractions10Fractions in Stories
Part of a GroupWhat Is LeftSharing a FractionScaling a RecipeRecap: Fraction Stories2Prime Factorization
Factor TreesUsing ExponentsOne Tree per NumberBigger NumbersRecap: Prime Factorization5Equivalent Fractions
Same Amount, New NameSimplifying FractionsSimplify in StepsComparing FractionsRecap: Equivalent Fractions3GCF and LCM
Greatest Common FactorGCF from Prime FactorsLeast Common MultipleLCM from Prime FactorsGCF or LCM?Recap: GCF and LCM6Adding and Subtracting
Same DenominatorDifferent DenominatorsSubtracting FractionsThe Least Common DenominatorNegative ResultsRecap: Adding and Subtracting9Mixed Numbers
Mixed to ImproperImproper to MixedAdding Mixed NumbersMultiplying Mixed NumbersRecap: Mixed Numbers