Divisibility
Divisibility rules and tests
Learning Objectives
Discussion Starters
Differentiation Ideas
Presentation Mode
lessons (2)
1
Divisibility Rules
Learn quick tricks to tell if a number divides evenly into another without doing long division.
Elementary25 minTeacher View
2
Divisibility by 2, 5, and 10
Learn the quick rules to tell if a number is divisible by 2, 5, or 10 just by looking at its last digit.
Elementary15 minTeacher View
Divisibility rules are shortcuts to determine if one number divides evenly into another without doing long division. These rules for 2, 3, 4, 5, 6, 8, 9, and 10 speed up mental math and are foundational for understanding factors and multiples.
What Students Will Learn
- Apply divisibility rules for 2, 3, 5, and 10
- Apply divisibility rules for 4, 6, 8, and 9
- Test divisibility without dividing
- Use divisibility to simplify fractions
- Solve problems using divisibility
Frequently Asked Questions
What is the rule for divisibility by 3?
A number is divisible by 3 if the SUM of its digits is divisible by 3.
What is the rule for divisibility by 4?
A number is divisible by 4 if its LAST TWO DIGITS form a number divisible by 4.
Why do divisibility rules work?
They exploit patterns in our base-10 number system.