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 minLesson

Definition

Divisibility rules are shortcuts that help us quickly determine if one number divides evenly into another without doing the actual division.

Divisibility by 2

A number is divisible by 2 if its last digit is even: or .

Divisibility by 5

A number is divisible by 5 if its last digit is or .

Divisibility by 10

A number is divisible by 10 if its last digit is .

Try it now

Which number is divisible by 2?

Worked Examples

Is 1,458 divisible by 2?

1

Look at the last digit

The last digit of is Last digit:

2

Check if it's even

Is in the set ?Yes, is even

3

Apply the rule

Since the last digit is even, is divisible by

Common Mistakes

Looking at the first digit instead of the last digit

Why it's wrong: For divisibility by 2, 5, and 10, only the last digit matters. The first digit tells us the size of the number, not its divisibility.

Correct: Always look at the rightmost (last) digit: in 847, check 7, not 8.

Thinking a number ending in 5 is divisible by 10

Why it's wrong: Divisibility by 10 is stricter than by 5. A number must end in 0 (not just 0 or 5) to be divisible by 10.

Correct: 75 is divisible by 5 but NOT by 10. Only 70, 80, 90... are divisible by 10.

Confusing 'even' with 'divisible by 10'

Why it's wrong: All numbers divisible by 10 are even, but not all even numbers are divisible by 10.

Correct: 24 is even (divisible by 2) but not divisible by 10. 20 is both even AND divisible by 10.

Interactive Visual

to

Click on numbers to select them. Adjust the range to explore different values.

Interactive Sandbox

Expression Calculator

Try these:

History

No calculations yet

Practice Problems

16 problems
Problem 1 of 16
Easy

Which number is divisible by 2?

Why It Matters

These divisibility rules save time and help you work smarter with numbers:
  • Mental math: Quickly check if you can split things evenly without a calculator
  • Simplifying fractions: Know instantly if you can divide both numerator and denominator by 2, 5, or 10
  • Real-world sharing: Can 24 cookies be shared equally between 2 friends? Can 35 students form groups of 5?
  • Building blocks: These simple rules prepare you for more complex divisibility tests (3, 4, 6, 9)
Mastering these three rules makes all your future math work faster!

Real World Applications

Sharing Equally

When splitting items between people, divisibility rules help you know instantly if it works.

Example:

Can 36 candies be shared equally between 2 children? Yes! ends in (even), so each.

1Try It Yourself

You have 125 stickers to put in packs of 5.

Can you make packs with no stickers left over?

Step 1: Write the mathematical expression

Check the last digit of 125:

Counting Money

Money often uses denominations of 10, making divisibility by 10 very practical.

Example:

If you have 240 cents, can you exchange them for dimes (10 cents)? Yes! ends in , so dimes.

2Try It Yourself

A piggy bank has 375 cents.

Can these be exchanged for an exact number of dimes?

Step 1: Write the mathematical expression

Check if 375 is divisible by 10:

Key Takeaways

  • 1A number is divisible by 2 if its last digit is even ()
  • 2A number is divisible by 5 if its last digit is or
  • 3A number is divisible by 10 if its last digit is
  • 4Every number divisible by 10 is also divisible by both 2 and 5
  • 5Only the last digit matters for these three rules

Frequently Asked Questions

Any number can be written as a multiple of 10 plus its last digit. For example, . Since is always divisible by 2, 5, and 10, we only need to check if the last digit () is divisible.
Any number can be written as a multiple of 10 plus its last digit. For example, . Since is always divisible by 2, 5, and 10, we only need to check if the last digit () is divisible.
Yes! Since , any number divisible by 10 must also be divisible by both 2 and 5. For example, 60 is divisible by 10, 5, and 2.
The same rules apply! 1,000,000 ends in 0, so it's divisible by 2, 5, AND 10. These rules work for numbers of any size.

Glossary

Divisible
A number is divisible by another if dividing them gives a whole number with no remainder
Even number
A number divisible by 2, ending in 0, 2, 4, 6, or 8
Odd number
A number not divisible by 2, ending in 1, 3, 5, 7, or 9
Last digit
The digit in the ones place (rightmost position)
Remainder
The amount left over after division

More in This Topic