Common Core State Standards:
4.OA.4 Find all factor pairs for a whole number in the range 1–100. Recognize that a whole number is a
multiple of each of its factors. Determine whether a given whole number in the range 1–100 is a multiple
of a given one-digit number. Determine whether a given whole number in the range 1–100 is prime or
• factor pair
• area model
In this unit, students will use their knowledge from 3rd grade on multiplication factors to help them find
factor pairs using area model/arrays. Students will use their knowledge of finding factor pairs to
determine if a number is prime or composite. In addition, for the first time students will learn about
prime and composite numbers in relation to rectangular arrays. Students will not be required to use the
standard algorithm until 5th grade.
Students will build on their understanding of addition and subtraction by using place value strategies to
make sense of the standard algorithms. They are expected to use a variety of models to support their
reasoning about numbers.
• Area Model/Arrays
• Relationship between multiplication & division (through various properties)
Video support can be found on LearnZillion.
o Find all the factor pairs of a number using area models
o Determine multiples of a number using area models
o Determine if a number is prime or composite using area models
Mrs. Ana Rhyne
I teach 4th grade math and science at Weatherstone Elementary School. I graduated from Meredith College with a BA in Spanish and K-6 licensure.