Finding Factors

Shodor > Interactivate > Lessons > Finding Factors


The following discussions and activities are designed to give students practice in finding the factors of whole numbers. The activities provide ample practice opportunities to reinforce the information from the discussions


Upon completion of this lesson, students will:

  • have learned about factors
  • have visually seen how factorizations make up various numbers

Standards Addressed:

Textbooks Aligned:

Student Prerequisites

  • Arithmetic: Student must be able to:
    • perform basic operations on whole numbers
    • understand visual representations of numbers
  • Technological: Students must be able to:
    • perform basic mouse manipulations such as point, click and drag
    • use a browser for experimenting with the activities

Teacher Preparation

  • Access to a browser
  • pencil and paper

Key Terms

factorAny of the numbers or symbols in mathematics that when multiplied together form a product. For example, 3 is a factor of 12, because 3 can be multiplied by 4 to give 12. Similarly, 5 is a factor of 20, because 5 times 4 is 20

Lesson Outline

  1. Focus and Review

    Remind students what has been learned in previous lessons that will be pertinent to this lesson and/or have them begin to think about the words and ideas of this lesson:

    • Ask students if anyone knows what a factor is
    • Using either the defintion a student gives, or one you provide yourself, ask if anyone knows what it means to factorize a number.

  2. Objectives

    Let the students know what it is they will be doing and learning today. Say something like this:

    • Today, class, we will be talking about factors
    • We are going to use the computers to learn about factors, but please do not turn your computers on or go to this page until I ask you to. I want to show you a little about this activity first.

  3. Teacher Input

    • Explain to the students how to do the assignment. You should model or demonstrate it for the students, especially if they are not familiar with how to use our computer applets.
    • Open your browser to Factorize in order to demonstrate this activity to the students.

  4. Guided Practice

    • Work through the first few questions on the Factorize Questions worksheet and then let them finish it on their own.
    • When you begin using the Factorize activity you may want to have students take turns giving answers to the problems and work through one or two games as a class until students are ready to try it on their own

  5. Independent Practice

    • Allow the students to work in groups of two. Monitor the room for questions and to be sure that the students are on the correct web site.

  6. Closure

    • You may wish to bring the class back together to discuss any problems that were especially hard for students to solve. Once the students have been allowed to share what they found, summarize once more the main points of the lesson.

Alternate Outline

This lesson can be rearranged in several ways if there is only one available computer:

  • This lesson can be rearranged in several ways if there is only one available computer: Have students complete paper worksheets that ask them to find the factors of certain numbers and use Factorize as a reward for two students at a time who have shown proficiency in solving the problems on paper.
  • Alternatively, select students who need additional practice to use the game. Teams of one strong student and one who needs help work well with this activity.

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