Final: The Missing Prime
Part of the Factors & Fractions section of Coddy's Pre-Algebra journey. Lesson 57 of 58.
Someone drew the factor tree of 84 all the way down to primes, then rubbed one prime out. The board shows the prime factorization with the missing prime as the letter n: two 2s, written as a power, a 3, and the gap. Find the prime that belongs in the gap and write your claim as a line, n equal to a number.
Challenge
The board shows the prime factorization of 84 with one prime missing: 2^2 × 3 × n = 84. Find the missing prime and type your claim, n equal to the number, then press Check.
Try it yourself
Solve for n
Test yourselfThis 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 Fractions8Dividing Fractions
How Many FitMultiply by the ReciprocalDividing by a Whole NumberHow Many BagsRecap: Dividing Fractions11Final Challenges
Final: Brackets and BarsFinal: Mixed and DividedFinal: The Gift RibbonFinal: The Missing PrimeFinal: Fractions on the Line