Open the App

Subjects

MathsMaths300 views·Updated Jun 12, 2026·6 pages

Learn How to Simplify Surds and Add or Subtract Them Easily

L
Lilly Nolan@lillynolan_kapb

A comprehensive guide to working with surds in mathematics, covering...

1
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Page 2: Adding and Subtracting Surds

The page explains the rules for combining like surds through addition and subtraction operations.

Highlight: Only surds with the same number inside the root can be added or subtracted.

Example: √80 + √125 can be simplified to 4√5 + 5√5 = 9√5

Definition: Like surds are surds that have the same number under the root sign.

Vocabulary: Terms - the parts of an expression separated by + or - signs.

2
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Page 3: Multiplying Surds

This section covers the multiplication of surds and how to simplify the results.

Definition: When multiplying surds, multiply the numbers outside the root signs together and the numbers inside the root signs together.

Example: 3√2 × 5√12 = 15√24 = 30√6

Highlight: Always simplify the final answer if possible by finding square factors.

3
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Page 4: Worded Problems with Surds

The page demonstrates how to apply surd operations to solve real-world problems, particularly focusing on area calculations.

Example: Finding the area of a triangle using surds: Area = ½ × base × height

Highlight: When expanding brackets containing surds, multiply each term carefully.

4
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Page 5: Dividing Surds

This section explains the process of dividing surds and rationalising denominators.

Definition: To divide surds, divide the numbers outside the root signs and divide the numbers inside the root signs separately.

Highlight: When dividing surds with two terms in the denominator, multiply both numerator and denominator by the conjugate of the denominator.

Example: 16√24 ÷ 8 = 2√3

5
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Page 6: Rationalising the Denominator

The final page focuses on the technique of rationalising denominators to eliminate surds from the bottom of fractions.

Definition: Rationalising the denominator means eliminating any surds from the denominator of a fraction.

Highlight: To rationalise a single surd denominator, multiply both numerator and denominator by the same surd.

Example: √3/√2 becomes (√3 × √2)/(√2 × √2) = √6/2

6
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Page 1: Simplifying Surds

This page introduces the fundamental concepts of simplifying surds through multiple examples. Students learn to break down numbers under square roots into their simplest form.

Definition: A surd is an expression that contains an irrational root, typically a square root that cannot be simplified to a whole number.

Highlight: Square numbers (1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144) are essential for simplifying surds.

Example: √8 can be simplified to 2√2 by identifying the largest square factor (4) and writing √8 as √4 × √2.

We thought you’d never ask...

What is the Knowunity AI companion?

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

Similar content

Most popular content: Simplifying Radicals

2

Most popular content in Maths

9
MathsMaths

Comprehensive Maths Concepts

Explore essential mathematical concepts including powers, geometry, statistics, and probability. This resource features 65 pages of detailed explanations, diagrams, and examples to enhance your understanding of topics such as right triangles, volume calculations, and data representation. Ideal for students seeking to strengthen their numeracy skills and grasp complex mathematical principles.

1080,0386,320
MathsMaths

GCSE Maths (Higher) // Revision Guide

The only GCSE maths (higher) revision guide you need to get a grade 9! Contains every topic, each with all potential question types and their solutions.

102,58760
M
MathsMaths

Medium Level alerbra

Master challenging maths concepts with this medium level flashcard set designed for grade 7/8 students. Strengthen your problem-solving skills and boost your confidence in maths!

78493
M
MathsMaths

Mastering Maths: Essential Concepts for Grade 10

Boost your math skills with this comprehensive flashcard set covering key concepts for grade 10. Perfect for exam preparation and building a strong foundation in mathematics.

105421
M
MathsMaths

Mastering Medium-Level Maths: Essential Flashcards for Grade 11 Students

Boost your Maths skills with this comprehensive set of flashcards designed specifically for Grade 11 students. Covering medium-level topics, these cards will help you ace your exams and build a solid foundation for advanced Maths.

119573
MathsMaths

Comprehensive Maths Concepts

Explore essential mathematical concepts including polynomial theorems, logarithmic properties, trigonometric functions, and integration techniques. This resource covers everything from solving inequalities to understanding exponential functions, providing a solid foundation for A-level mathematics. Ideal for students aiming for top grades.

1222,0161,817
P
MathsMaths

Percentage,fractions and decimals

how well do you know percentages,fractions and decimals

73123
M
MathsMaths

Maths Made Easy: Essential Concepts for Grade 7

Master key mathematical concepts with this comprehensive flashcard set designed specifically for 13-year-old students. Strengthen your understanding and ace your exams!

77612
M
MathsMaths

maths SOHCAHTOA

Trigonometric ratios SOHCAHTOA for calculating angles and sides in right-angled triangles.

112230

Most popular content

9
SociologySociology

Sociology of Education Overview

Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.

12102,8423,040
SociologySociology

Sociology of Families: Comprehensive Revision

Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.

1273,6392,306
CriminologyCriminology

Criminology: Crime & Punishment Overview

Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.

1254,8641,059
SociologySociology

Comprehensive Crime & Deviance Overview

Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.

1251,6501,399
C
BiologyBiology

Cell Biology and Cell structure

cell structures

93,2290
English LiteratureEnglish Literature

An Inspector Calls: Character Insights

Explore in-depth analysis and key quotes for characters in J.B. Priestley's 'An Inspector Calls'. This resource covers Gerald Croft, Inspector Goole, Sheila Birling, Mrs. Birling, Eric Birling, and Eva Smith, focusing on themes of class, gender roles, and social responsibility. Ideal for students aiming for Grade 8 and above.

1025,419907
CriminologyCriminology

WJEC Unit 4 Criminology

Criminology unit 4 detailed revision note

127,147125
CriminologyCriminology

Criminology Theories Overview

Explore key criminology theories and their implications on crime and deviance. This comprehensive summary covers biological, psychological, and sociological perspectives, including labelling theory, right realism, and the impact of social campaigns on policy development. Ideal for A-Level criminology students seeking to understand the complexities of criminal behaviour and the factors influencing crime prevention strategies.

129,758210
English LiteratureEnglish Literature

Romeo and Juliet: Key themes

Key Romeo and Juliet themes and analysed quotes

106,702198

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.6/5App Store
4.7/5Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan SiOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha KlichAndroid user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

AnnaiOS user

MathsMaths300 views·Updated Jun 12, 2026·6 pages

Learn How to Simplify Surds and Add or Subtract Them Easily

L
Lilly Nolan@lillynolan_kapb

A comprehensive guide to working with surds in mathematics, covering simplification, operations, and rationalisation. This essential mathematical concept helps students understand how to manipulate expressions containing square roots effectively.

• Learn how to simplify surds in mathby breaking down...

1
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

Page 2: Adding and Subtracting Surds

The page explains the rules for combining like surds through addition and subtraction operations.

Highlight: Only surds with the same number inside the root can be added or subtracted.

Example: √80 + √125 can be simplified to 4√5 + 5√5 = 9√5

Definition: Like surds are surds that have the same number under the root sign.

Vocabulary: Terms - the parts of an expression separated by + or - signs.

2
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

Page 3: Multiplying Surds

This section covers the multiplication of surds and how to simplify the results.

Definition: When multiplying surds, multiply the numbers outside the root signs together and the numbers inside the root signs together.

Example: 3√2 × 5√12 = 15√24 = 30√6

Highlight: Always simplify the final answer if possible by finding square factors.

3
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

Page 4: Worded Problems with Surds

The page demonstrates how to apply surd operations to solve real-world problems, particularly focusing on area calculations.

Example: Finding the area of a triangle using surds: Area = ½ × base × height

Highlight: When expanding brackets containing surds, multiply each term carefully.

4
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

Page 5: Dividing Surds

This section explains the process of dividing surds and rationalising denominators.

Definition: To divide surds, divide the numbers outside the root signs and divide the numbers inside the root signs separately.

Highlight: When dividing surds with two terms in the denominator, multiply both numerator and denominator by the conjugate of the denominator.

Example: 16√24 ÷ 8 = 2√3

5
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

Page 6: Rationalising the Denominator

The final page focuses on the technique of rationalising denominators to eliminate surds from the bottom of fractions.

Definition: Rationalising the denominator means eliminating any surds from the denominator of a fraction.

Highlight: To rationalise a single surd denominator, multiply both numerator and denominator by the same surd.

Example: √3/√2 becomes (√3 × √2)/(√2 × √2) = √6/2

6
of 6
sunds

Simplifying surds

(e.g. Simplify the following

are:
Nore: The square numbers
1, 4, 9, 16, 25,
36, 49, 64, 81, 100,
121 and 144.

1)

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

Page 1: Simplifying Surds

This page introduces the fundamental concepts of simplifying surds through multiple examples. Students learn to break down numbers under square roots into their simplest form.

Definition: A surd is an expression that contains an irrational root, typically a square root that cannot be simplified to a whole number.

Highlight: Square numbers (1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144) are essential for simplifying surds.

Example: √8 can be simplified to 2√2 by identifying the largest square factor (4) and writing √8 as √4 × √2.

We thought you’d never ask...

What is the Knowunity AI companion?

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

Similar content

Most popular content: Simplifying Radicals

2

Most popular content in Maths

9
MathsMaths

Comprehensive Maths Concepts

Explore essential mathematical concepts including powers, geometry, statistics, and probability. This resource features 65 pages of detailed explanations, diagrams, and examples to enhance your understanding of topics such as right triangles, volume calculations, and data representation. Ideal for students seeking to strengthen their numeracy skills and grasp complex mathematical principles.

1080,0386,320
MathsMaths

GCSE Maths (Higher) // Revision Guide

The only GCSE maths (higher) revision guide you need to get a grade 9! Contains every topic, each with all potential question types and their solutions.

102,58760
M
MathsMaths

Medium Level alerbra

Master challenging maths concepts with this medium level flashcard set designed for grade 7/8 students. Strengthen your problem-solving skills and boost your confidence in maths!

78493
M
MathsMaths

Mastering Maths: Essential Concepts for Grade 10

Boost your math skills with this comprehensive flashcard set covering key concepts for grade 10. Perfect for exam preparation and building a strong foundation in mathematics.

105421
M
MathsMaths

Mastering Medium-Level Maths: Essential Flashcards for Grade 11 Students

Boost your Maths skills with this comprehensive set of flashcards designed specifically for Grade 11 students. Covering medium-level topics, these cards will help you ace your exams and build a solid foundation for advanced Maths.

119573
MathsMaths

Comprehensive Maths Concepts

Explore essential mathematical concepts including polynomial theorems, logarithmic properties, trigonometric functions, and integration techniques. This resource covers everything from solving inequalities to understanding exponential functions, providing a solid foundation for A-level mathematics. Ideal for students aiming for top grades.

1222,0161,817
P
MathsMaths

Percentage,fractions and decimals

how well do you know percentages,fractions and decimals

73123
M
MathsMaths

Maths Made Easy: Essential Concepts for Grade 7

Master key mathematical concepts with this comprehensive flashcard set designed specifically for 13-year-old students. Strengthen your understanding and ace your exams!

77612
M
MathsMaths

maths SOHCAHTOA

Trigonometric ratios SOHCAHTOA for calculating angles and sides in right-angled triangles.

112230

Most popular content

9
SociologySociology

Sociology of Education Overview

Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.

12102,8423,040
SociologySociology

Sociology of Families: Comprehensive Revision

Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.

1273,6392,306
CriminologyCriminology

Criminology: Crime & Punishment Overview

Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.

1254,8641,059
SociologySociology

Comprehensive Crime & Deviance Overview

Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.

1251,6501,399
C
BiologyBiology

Cell Biology and Cell structure

cell structures

93,2290
English LiteratureEnglish Literature

An Inspector Calls: Character Insights

Explore in-depth analysis and key quotes for characters in J.B. Priestley's 'An Inspector Calls'. This resource covers Gerald Croft, Inspector Goole, Sheila Birling, Mrs. Birling, Eric Birling, and Eva Smith, focusing on themes of class, gender roles, and social responsibility. Ideal for students aiming for Grade 8 and above.

1025,419907
CriminologyCriminology

WJEC Unit 4 Criminology

Criminology unit 4 detailed revision note

127,147125
CriminologyCriminology

Criminology Theories Overview

Explore key criminology theories and their implications on crime and deviance. This comprehensive summary covers biological, psychological, and sociological perspectives, including labelling theory, right realism, and the impact of social campaigns on policy development. Ideal for A-Level criminology students seeking to understand the complexities of criminal behaviour and the factors influencing crime prevention strategies.

129,758210
English LiteratureEnglish Literature

Romeo and Juliet: Key themes

Key Romeo and Juliet themes and analysed quotes

106,702198

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.6/5App Store
4.7/5Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan SiOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha KlichAndroid user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

AnnaiOS user