Activity
Math Is Fun

Math Is Fun: Divisibility Rules

For Students 3rd - 8th
A chart that overviews divisibility rules for numbers divisible by numbers 2 through 12. Simple rules accompanied by examples.
eBook
Khan Academy

Khan Academy: Intro to Factors & Divisibility

For Students 9th - 10th Standards
Learn what it means for polynomials to be factors of other polynomials or to be divisible by them.
Unknown Type
Khan Academy

Khan Academy: Factors & Divisibility

For Students 9th - 10th Standards
Students practice multiple-choice problems with factors and divisibility.
Activity
National Council of Teachers of Mathematics

The Math Forum: Beat the Calculator: Adding Even Numbers

For Students 4th - 6th Standards
Can you beat the calculator? Your task is to find the sum of all even numbers between two and any selected two-digit even number. If you can find the number pattern, you are sure to beat the calculator every time. Links to other "Beat...
Activity
AAA Math

Aaa Math: Counting Even Numbers by Twos

For Students K - 1st Standards
Use this lesson to learn about adding two and skip counting to understanding the concepts of counting even numbers by twos. Play the interactive game "Counting Up By Twos," and get your score instantly.
Graphic
Other

Project Happy Child: 100s Board Worksheets

For Students Pre-K - 1st Standards
Use these 100s Boards to have students check for divisibility by 2-12 and for square and prime numbers. Just find the links below the 100s board that has the directions printed right on top of the worksheet.
Activity
Lawrence Hall of Science

The Math Page: Skill in Arithmetic: The Meaning of Division

For Students 3rd - 8th
This Math Page tutorial explains and defines the concept of division. There is a practice section at the end of the lesson.
Activity
The Math League

The Math League: Whole Numbers & Basic Properties

For Students 3rd - 8th Standards
Here is a nice resource for students and teachers about whole numbers and their basic properties. It provides links to information on place value, expanded form, and rounding numbers are just a few of the topics on this page.
Activity
AAA Math

Aaa Math: All About Division

For Students 3rd - 8th Standards
These tutorials teach division operations covered in K8 math courses. Each section has an explanation, interactive practice and challenge games about division.
Lesson Plan
George Mason University

Margo Mankus: Investigating Lcm and Gcf Using Rods

For Teachers 9th - 10th Standards
This lesson plan is for an activity using rods (Cuisenaire Bars) to help students understand the concept of factors, in particular the LCM and GCF of two numbers.
Activity
University of Cambridge

University of Cambridge: Nrich: Two Primes Make One Square

For Students 3rd - 8th
On this one page website sharpen your logic, prime numbers and square numbers skills while working on this challenge. The solution is available to double check your solution.
Activity
University of Cambridge

University of Cambridge: Nrich: A Conversation Piece

For Students 3rd - 8th Standards
On this one page website sharpen your logic, division and prime number recognition skills while working on this challenge. The solution is available to double check your solution.
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Other

Project Happy Child: Times Tables Division Worksheets

For Students Pre-K - 1st Standards
50 basic division worksheets are available at this web site. They can be printed and used for a variety of practice purposes. Some helpful hints are included to avoid mindless practice that could quickly become counter productive.
Activity
University of Cambridge

University of Cambridge: Nrich: Divide It Out!

For Students Pre-K - 1st Standards
On this one page website sharpen your logic and basic division fact skills while working on this challenge. The solution is available to double check your solution.