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What Is a Factor – Maths Definition, Examples for Kids

Freddie Jack Bennett • 2026-04-26 • Reviewed by Oliver Bennett






What Is a Factor in Math? Definition, Examples for Kids & Factors of 10, 18, 20, 96

A factor in mathematics is a whole number that divides another number exactly, leaving no remainder. When you multiply two factors together, they produce the original number. This fundamental concept helps students understand division, multiplication, and number relationships.

Factors appear throughout arithmetic and form the building blocks for more advanced topics like prime numbers, fractions, and algebra. Whether simplifying fractions or finding common denominators, the principle remains the same: identifying numbers that divide evenly into a given value. Understanding factors also makes it easier to break down complex problems into smaller, manageable parts.

What is a factor in maths?

÷
Definition
A number that divides another number exactly with no remainder

Key Rule
Factors never leave a remainder when dividing

×
Examples
1, 2, 5, and 10 are all factors of 10

Use
Simplify calculations and understand multiplication relationships

Key properties of factors

  • Every number’s smallest factor is always 1, and its largest is itself
  • Except for 0 and 1, every number has at least two factors: 1 and itself
  • Factors come in pairs that multiply together to produce the original number
  • Factors are always less than or equal to the number they divide
  • The number of factors varies depending on the specific number
  • Prime factors are the prime numbers that multiply to create the original number
  • Understanding factors helps with simplifying fractions and finding common denominators
Number Factors Factor Pairs (Positive)
10 1, 2, 5, 10 (1×10), (2×5)
18 1, 2, 3, 6, 9, 18 (1×18), (2×9), (3×6)
20 1, 2, 4, 5, 10, 20 (1×20), (2×10), (4×5)
96 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96 (1×96), (2×48), (3×32), (4×24), (6×16), (8×12)
Understanding factor pairs

Factor pairs are two numbers that multiply together to equal the original number. For 18, the pairs are (1, 18), (2, 9), and (3, 6). These pairs are useful because they show the two ways of thinking about division and multiplication for any given factor relationship.

What is a factor example?

Looking at concrete examples makes it easier to understand how factors work in practice. Each number has its own set of factors that divide evenly into it, and examining these systematically reveals patterns that apply across all numbers.

Factors of 10

The number 10 has exactly four factors: 1, 2, 5, and 10. When dividing 10 by any of these numbers, the result is always a whole number with no remainder. The factor pairs for 10 are (1, 10) and (2, 5), which multiply together to give 10. This makes 10 particularly useful for understanding basic multiplication tables and for teaching division concepts.

Factors of 18

Eighteen has six factors: 1, 2, 3, 6, 9, and 18. Its factor pairs are (1, 18), (2, 9), and (3, 6). The prime factorisation of 18 is 2 × 3², meaning it is built from one factor of 2 and two factors of 3. Understanding the prime factorisation of 18 helps in simplifying fractions and finding common multiples.

Factors of 20

The number 20 has six factors: 1, 2, 4, 5, 10, and 20. These produce the factor pairs (1, 20), (2, 10), and (4, 5). Twenty is often used in educational settings because it connects to the decimal system, making it intuitive for students to visualise and work with. Its factors also relate to common measurements like centimetres and millimetres.

Factors of 96

Ninety-six has twelve factors: 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, and 96. This larger set demonstrates how composite numbers have more factors than prime numbers. The factor pairs for 96 include (1, 96), (2, 48), (3, 32), (4, 24), (6, 16), and (8, 12). This breadth of factors makes 96 useful for exercises involving division and for demonstrating how larger numbers break down into smaller components.

Prime factors explained

Prime factors are the prime numbers that multiply together to create the original number. For 18, the prime factors are 2 and 3, shown as 2 × 3². Prime factors form the building blocks of any number and help distinguish between prime and composite numbers.

What is a factor for kids?

For younger learners, factors can be explained through everyday examples like sharing objects evenly. If six candies can be divided into groups of 2 with no leftovers, then 2 is a factor of 6. Similarly, arranging 6 items into 1 group of 6, 2 groups of 3, 3 groups of 2, or 6 groups of 1 shows all the ways the number can be divided fairly.

Real-life situations make factors tangible for children. When distributing chocolates or sweets among friends, the goal is to share them evenly without any leftovers. The numbers that allow this fair distribution are the factors. This practical approach aligns with how math education platforms introduce the concept to young learners.

Teaching factors to children

  • Use physical objects like blocks or candies to demonstrate grouping
  • Draw factor trees or T-charts to visually organise factor pairs
  • Start with small numbers before moving to larger ones
  • Connect factors to division facts the child already knows
  • Reinforce that factors always come in pairs that multiply to the original number
  • Practice with numbers that have clear factor patterns like 12, 20, or 24
Factor discovery method

A practical way to find all factors is to test divisors from 1 up to the square root of the target number. For 20, testing 1 through 4 (since √20 ≈ 4.5) reveals the factors on one side, then simply pair them with their counterparts to find all factors: 20÷1=20, 20÷2=10, 20÷3 has a remainder, 20÷4=5.

How to find factors

Finding factors systematically involves checking which numbers divide evenly into your target. Begin with 1 and test successive whole numbers, keeping those that divide without a remainder. Stop when you reach the square root of the number, since any factor larger than that would have already been paired with a smaller one.

  1. List all integers starting from 1 up to the target number
  2. Divide the target by each candidate number
  3. Record numbers that divide with zero remainder
  4. Continue until reaching the square root of the target
  5. Pair each found factor with its counterpart to complete the list
  6. Verify by multiplying factor pairs to confirm they equal the original number
Short division method

Prime factorisation offers another approach: repeatedly divide by the smallest prime numbers until reaching 1. For 96, this gives 96÷2=48, 48÷2=24, 24÷2=12, 12÷2=6, 6÷2=3, 3÷3=1. The prime factors of 96 are 2⁵ × 3.

Established facts and common questions

What is certain about factors
  • 1 and the number itself are always factors
  • Factors divide evenly with no remainder
  • Factors come in pairs that multiply to the original number
  • Zero and one have unique factor properties
  • Factors are always whole numbers
Common misconceptions
  • Factors are not the same as multiples
  • Not all divisors are called factors in some contexts
  • Negative factors exist but are often excluded in basic lessons
  • Factor pairs are typically listed as positive pairs only
  • The smallest factor of any number is always 1

Why factors matter in mathematics

Factors serve as the foundation for numerous mathematical concepts and operations. When simplifying fractions, identifying common factors between the numerator and denominator allows reduction to lowest terms. Finding the greatest common factor of two numbers helps solve problems involving ratios, proportions, and fair division.

Understanding factors also prepares students for algebra, where factoring expressions becomes essential for solving equations. Polynomials are factored using many of the same principles that apply to whole numbers. The relationship between factors and multiples extends into topics like least common multiples, which are crucial for adding and subtracting fractions with different denominators.

Educational resources for learning factors

Students and educators can access a variety of materials to strengthen their understanding of factors. Interactive platforms like SplashLearn offer definitions and examples tailored to different age groups. Visual learning tools and video explanations demonstrate factor relationships through animations and practical examples.

Reference materials such as A Maths Dictionary for Kids provide quick definitions suitable for younger learners, while platforms like Khan Academy offer structured courses covering factors, multiples, and their relationships. These resources complement classroom instruction and provide additional practice opportunities.

Video and visual resources

  • YouTube tutorials demonstrate factor trees and T-chart methods
  • Interactive factor calculators check work automatically
  • Mathematical dictionaries provide quick reference definitions
  • Educational games make factor practice engaging
  • Worksheet generators offer unlimited practice problems

Summary

A factor is a whole number that divides another number exactly, producing no remainder. Factors work in pairs that multiply together to equal the original number, and every number has at least two factors: 1 and itself. Understanding factors builds essential skills for division, multiplication, fractions, and algebra. Practice with examples like the factors of 10, 18, 20, and 96 helps reinforce these concepts for students at all levels. For those studying currency conversions alongside mathematical concepts, exploring resources on UAE Dirham to GBP and 100 Euros in Pounds provides practical applications of numerical understanding.

Frequently asked questions

What is a factor in maths?

A factor is a whole number that divides another number exactly without leaving a remainder. For example, 3 is a factor of 12 because 12 ÷ 3 = 4 with no remainder.

What are the factors of 10?

The factors of 10 are 1, 2, 5, and 10. The factor pairs are (1, 10) and (2, 5).

What are the factors of 18?

The factors of 18 are 1, 2, 3, 6, 9, and 18. The factor pairs are (1, 18), (2, 9), and (3, 6).

What are the factors of 20?

The factors of 20 are 1, 2, 4, 5, 10, and 20. The factor pairs are (1, 20), (2, 10), and (4, 5).

What are the factors of 96?

The factors of 96 are 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, and 96. This is a larger set due to 96 being a highly composite number.

How do you find factors of a number?

To find factors, test each number from 1 upward by dividing. If the division results in a whole number with no remainder, it is a factor. Stop testing when you reach the square root of the number.

What is the difference between factors and multiples?

Factors are numbers that divide into a given number, while multiples are numbers that the given number divides into. For 6, factors are 1, 2, 3, and 6, while multiples include 6, 12, 18, and beyond.

How do you explain factors to children?

Use examples like sharing candies evenly. If 6 candies can be divided into groups of 2 with none left over, then 2 is a factor of 6. Physical objects help children visualise the concept.

What are prime factors?

Prime factors are prime numbers that multiply together to equal the original number. For 18, the prime factors are 2 and 3, expressed as 2 × 3².

What is the smallest factor of any number?

The smallest factor of any number is always 1. The largest factor of any number is the number itself. These two factors are present in every non-zero number.



Freddie Jack Bennett

About the author

Freddie Jack Bennett

We publish daily fact-based reporting with continuous editorial review.