5.6.3

Adding & Subtracting Fractions

Test yourself

Adding and Subtracting Fractions With the Same Denominator

When we add or subtract fractions, we must make sure the denominator of both fractions is the same.

Illustrative background for E.g.1 Same denominatorIllustrative background for E.g.1 Same denominator ?? "content

E.g.1 Same denominator

  • If the denominator of both fractions is already the same we simply add or subtract the numerators.
Illustrative background for What is $$\frac{4}{5} - \frac{1}{5}$$?Illustrative background for What is $$\frac{4}{5} - \frac{1}{5}$$? ?? "content

What is 45−15\frac{4}{5} - \frac{1}{5}?

  • The denominators are the same so we just need to subtract the numerators (4 − 1 = 3).
  • Keep the denominator the same.

Adding and Subtracting Fractions With Different Denominators

When we add or subtract fractions, we must make sure the denominator of both fractions is the same.

Illustrative background for Example 1Illustrative background for Example 1 ?? "content

Example 1

  • If the denominators are NOT the same, we need to make them the same using an equivalent fraction.
Illustrative background for Example 1Illustrative background for Example 1 ?? "content

Example 1

  • When finding an equivalent fraction we must multiply or divide both the top and bottom row by the same amount.
Illustrative background for Example 1Illustrative background for Example 1 ?? "content

Example 1

  • Once both the fractions have the same denominator, we can add or subtract the numerators.
Illustrative background for What is $$\frac{3}{4} - \frac{1}{5}$$?Illustrative background for What is $$\frac{3}{4} - \frac{1}{5}$$? ?? "content

What is 34−15\frac{3}{4} - \frac{1}{5}?

  • We cannot do the subtraction straight away because the fractions do NOT have the same denominator.
Illustrative background for What is $$\frac{3}{4} - \frac{1}{5}$$?Illustrative background for What is $$\frac{3}{4} - \frac{1}{5}$$? ?? "content

What is 34−15\frac{3}{4} - \frac{1}{5}?

  • Using equivalent fractions, convert the fraction so that they have the same denominator.
Illustrative background for What is $$\frac{3}{4} - \frac{1}{5}$$?Illustrative background for What is $$\frac{3}{4} - \frac{1}{5}$$? ?? "content

What is 34−15\frac{3}{4} - \frac{1}{5}?

  • Once both the fractions have the same denominator, we can add or subtract the numerators.

Jump to other topics

1Year 5 - Number

1.1Number & Place Value

1.1.1The Value of Digits to Millions

1.1.2Smallest & Biggest Numbers to Millions

1.1.3Ordering Numbers to Millions

1.1.4Counting in Powers of 10

1.1.5Counting in Negative Numbers

1.1.6Rounding Numbers up to 1,000,000

1.1.7Reading Roman Numerals

1.2Addition & Subtraction

1.2.1Written Methods for Adding Large Numbers

1.2.2Written Methods for Subtracting Large Numbers

1.2.3Mental Addition & Subtraction

1.2.4Rounding to Check Your Answer

1.3Multiplication & Division

1.3.1Multiples

1.3.2Factors

1.3.3Prime Numbers

1.3.4Prime Factors

1.3.5Composite Numbers

1.3.6Factor Trees

1.3.7Multiplication by a 1 Digit Number

1.3.8Long Multiplication Using Column Method

1.3.9Times Tables

1.3.10Division

1.3.11Multiplying & Dividing by 10, 100 & 1,000

1.3.12Square & Cube Numbers

1.4Fractions & Decimals

1.4.1Compare & Order Fractions

1.4.2Identifying Equivalent Fractions

1.4.3Add & Subtract Fractions

1.4.4Mixed Numbers & Improper Fractions

1.4.5Multiplying Fractions by Whole Numbers

1.4.6Converting Between Decimals & Fractions

1.4.7Rounding Decimals

1.4.8Ordering Decimals

2Year 5 - Measurement

2.1Measures

2.1.1Metric Measurements

2.1.2Imperial Measurements

2.2Perimeter & Area

2.2.1Perimeter

2.2.2Area

2.3Time

2.3.1Units of Time

3Year 5 - Geometry

3.1Properties of 3D Shapes

3.1.1Types of 3D Shapes

3.1.2Faces, Edges & Vertices

3.2Properties of 2D Shapes

3.2.1Polygons

3.3Angles

3.3.1Angles in Degrees

3.3.2Types of Angle

3.3.3Finding Missing Angles

3.4Position & Direction

3.4.1Reflection & Translation

4Year 5 - Statistics

4.1Graphs

4.1.1Line Graphs

4.1.2Tables

4.1.3Timetables

5Year 6 - Number

5.1Number & Place Value

5.1.1The Value of Digits to Ten Millions

5.1.2Ordering Numbers to Millions

5.1.3Rounding

5.1.4Negative Numbers

5.2Multiplication & Division

5.2.1Multiplication by a 2 Digit Number

5.2.2Division

5.2.3Multiples

5.2.4Factors

5.2.5Primes

5.3Mental Maths

5.3.1Multiplying & Dividing by 10, 100 & 1,000

5.3.2Addition & Subtraction

5.3.3Adding & Subtracting 10, 100 & 1,000

5.3.4Multiplication & Division

5.4Order of Operations

5.4.1BIDMAS

5.5Problem Solving

5.5.1Addition & Subtraction Multi-step Problems

5.5.2Problem Solving with Proportion

5.6Fractions & Decimals

5.6.1Simplifying Fractions Using Equivalents

5.6.2Ordering Different Types of Fraction

5.6.3Adding & Subtracting Fractions

5.6.4Adding & Subtracting Mixed Numbers

5.6.5Multiplying Fractions

5.6.6Dividing Fractions by Whole Numbers

5.6.7Converting Between Decimals & Fractions

5.6.8Dividing Decimals

6Year 6 - Ratio & Proportion

6.1Ratio

6.1.1Using Ratios

6.1.2Simplifying Ratios

6.2Percentages

6.2.1Calculating Percentages

6.3Scale

6.3.1Scale of 2D Shapes

7Year 6 - Algebra

7.1Sequences

7.1.1Describing Sequences

7.1.2Finding Gaps in Sequences

7.2Missing Number Problems

7.2.1Missing Number Problems

7.3Equations

7.3.1Balancing Equations

7.3.2Combining Two Variables

8Year 6 - Measurement

8.1Problem Solving

8.1.1Problem Solving with Measures

8.2Unit Conversion

8.2.1Conversion Between Miles & Kilometres

8.3Perimeter, Area & Volume

8.3.1Area

8.3.2Volume

8.3.3Nets

8.3.4Faces, Edges & Vertices

8.4Angles

8.4.1Types of Angle

8.4.2Finding Missing Angles

8.4.3Finding Missing Angles in Triangles

8.4.4Vertically Opposite Angles

8.5Circles

8.5.1Parts of a Circle

8.6Coordinate Grids

8.6.1Positions on Coordinate Grids

8.6.2Reflection & Translation

9Year 6 - Statistics

9.1Displaying Data

9.1.1Pie Charts

9.1.2Line Graphs

9.2Averages

9.2.1Mean

Unlock your full potential with Seneca Premium

  • Unlimited access to 10,000+ open-ended exam questions

  • Mini-mock exams based on your study history

  • Unlock 800+ premium courses & e-books

Get started with Seneca Premium

Ordering Different Types of Fraction

Adding & Subtracting Mixed Numbers