Grade levels 

Factorization Forest Lesson Plan

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Grade Level:

4- 5


The “Factorization Forest” game will help students practice the skills of Prime Factorization. Students will be able to correctly identify prime factors through the use the factor tree strategy. Students will also be able to correctly identify prime and composite numbers.

Common Core Standards:



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 composite.


Warm-Up Activities: 

Whole Class Activity: (Interactive Whiteboard or a Projector to Project the Web-Site)
Pass out dry erase boards to pairs of students or individual students. Students will be using their boards to show their work throughout the warm-up activities.

The teacher can begin with a quick review of the factorization that they are currently working on in class. Use the following link as a warm-up activity.

Let a student pick a number to be factorized. Place it in the interactive activity box found at the above link. Then, ask the students to use a factor tree to show the correct factorization of the selected number. Once all students have tried to factor the number click on “Factorize Button”. Students can then check their answers on their dry erase boards. Continue the warm-up activity until you feel that students are ready to play the game “Factorization Forest” either as a whole group, individually, or as partners in a computer lab setting.

Main Activity:

Watch the instructional video at before having students play the game. Explain the two modes. Students can play the “Factorization Forest” game either as a whole group or on individual computers. If you are working as a whole group, each student could continue to work the problems out on a dry erase board and then hold up their answers. If they are working in pairs or individually, they could still use a dry erase board to work on their problems. If they are working in pairs, they can then compare answers.


Have students complete the attached Factor Tree Forest Worksheet.