Virginia SOL 5.NS.2.b
The Standard
Classify, compare, and contrast whole numbers up to 100 using the characteristics prime and composite.
Virginia Standards of Learning for Mathematics · The student will demonstrate an understanding of prime and composite numbers, and determine the prime factorization of a whole number up to 100.
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students find factor pairs for whole numbers. They use those pairs to decide whether each number is prime or composite and explain how two numbers differ. They recognize that 1 is neither.
What Mastery Looks Like
- A student lists complete factor pairs without repeats. They identify a prime number as having exactly two factors and a composite number as having more than two. They explain why 1 is neither.
Common Misconceptions
- Students may think every odd number is prime or every even number is composite. They often call 1 prime because it has one factor. Some confuse factors with multiples or stop checking before finding all factor pairs.
How to Assess It
- Exit ticket: List the factor pairs for 17 and 27, classify each number, and write one sentence comparing them. Explain why 1 belongs to neither group.
Lesson moves
Ways to Teach It
Give pairs 36 counters and number cards; students build equal arrays for each number, record factor pairs, then label it prime or composite.
Ask, “Is every odd number prime?” and have students use 9, 15, 17, and 21 as evidence in a written response.
Play Prime or Composite Sort with cards 1 through 100; students place each card, then defend one choice by naming its factors.
Plan equal rows for 29, 30, and 31 chairs, then connect possible arrangements to prime and composite labels.
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Printable 5.NS.2.b Worksheet
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Related Standards
- 5.NS.2
The student will demonstrate an understanding of prime and composite numbers, and determine the prime factorization of a whole number up to 100.
- 5.NS.2.a
Given a whole number up to 100, create a concrete or pictorial representation to demonstrate whether the number is prime or composite, and justify reasoning.
- 5.NS.2.c
Determine the prime factorization for a whole number up to 100.
- 2.NS.2.e
Compose and decompose whole numbers up to 200 by making connections between a variety of models (e.g., base 10 blocks, place value cards, presented orally, in e...
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