Virginia SOL 5.CE.2.a
The Standard
Determine the least common multiple of two numbers to find the least common denominator for two fractions.
Virginia Standards of Learning for Mathematics · The student will estimate, represent, solve, and justify solutions to single-step and multistep problems, including those in context, using addition and subtraction of fractions with like and unlike denominators (with and without models), and solve single-step contextual problems involving multiplication of a whole number and a proper fraction, with models.
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students generate multiples of each denominator and identify the smallest value both lists share. They use that value as a common denominator and rewrite each fraction with an equivalent numerator.
What Mastery Looks Like
- Given two fractions, students can find the smallest shared multiple of the denominators by listing multiples or using factor relationships. They choose 12, not 24, for fourths and sixths and can explain why.
Common Misconceptions
- Students may confuse factors with multiples or choose a shared factor instead of a shared multiple. Some multiply the denominators and stop, even when a smaller common denominator exists. Others use the numerators when finding the common denominator.
How to Assess It
- Exit ticket: Find the least common denominator of 3/8 and 5/12, show how you know, then rewrite both fractions using it.
Lesson moves
Ways to Teach It
Pairs mark multiples on two colored number strips, then circle the first shared value and use it as the denominator.
Ask why 24 is the least common denominator for eighths and twelfths, while 48 is common but not least.
Play LCD Match: students draw two fraction cards, name the least common denominator, and earn a point by showing the multiples.
Compare 3/4 cup and 5/6 cup on a measuring-cup diagram by rewriting both amounts in twelfths.
Free download
Printable 5.CE.2.a Worksheet
A ready-to-print activity worksheet aligned to 5.CE.2.a, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetKeep exploring
Related Standards
- 4.CE.3.a
Estimate and determine the sum or difference of two fractions (proper or improper) and/or mixed numbers, having like denominators limited to 2, 3, 4, 5, 6, 8, 1...
- 3.NS.3.g
Compare two fractions (proper or improper) and/or mixed numbers with like denominators of 2, 3, 4, 5, 6, 8, and 10 (e.g., 3 6 < 4 6 ) using words (greater than,...
- 4.CE.2.f
Determine common factors and the greatest common factor of no more than three numbers.
- 5.CE.2.b
Estimate and determine the sum or difference of two fractions (proper or improper) and/or mixed numbers, having like and unlike denominators limited to 2, 3, 4,...
Turn this exact standard into a lesson
Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.