Prime and Composite Numbers
Grade 4 · Math · Factors and Multiples · Delaware, USA
Lesson Summary
A prime number has exactly two factors: 1 and itself. A composite number has more than two factors.
Explanation
The number 7 is prime because its only factors are 1 and 7. The number 12 is composite because it has factors 1, 2, 3, 4, 6, and 12. The number 1 is special: it is neither prime nor composite because it only has one factor. The smallest prime number is 2, and it is also the only even prime number. All other even numbers are composite because they can be divided by 2.
Practice Questions
Q1: Is 11 prime or composite?
Answer: Prime, because its only factors are 1 and 11.
Q2: Is 15 prime or composite?
Answer: Composite, because it has factors 1, 3, 5, and 15.
Q3: Name three prime numbers less than 20.
Answer: Possible answers include 2, 3, 5, 7, 11, 13, 17, or 19 (any three of these).
People Also Ask
What is Prime and Composite Numbers in Grade 4 Math?+
Prime and Composite Numbers is a lesson in the Factors and Multiples chapter of Grade 4 Math. It is part of the Delaware, USA school curriculum and covers key concepts that students need to understand at this level.
What grade level covers Prime and Composite Numbers?+
Prime and Composite Numbers is taught in Grade 4 as part of the Math curriculum in Delaware, USA.
How can I help my child with Factors and Multiples in Math?+
Start with the lesson summary and explanation on this page. Practice the questions provided, then use TutorTom for personalized, step-by-step help with Factors and Multiples topics.