Adding Negative Fractions

In the fascinating world of mathematics, fractions play a crucial role in representing parts of a whole. However, when negative numbers are introduced, the concept of adding negative fractions may seem like a daunting task for Grade 7 students.

Fear not! By understanding the principles and strategies involved, adding negative fractions can become a valuable skill that opens doors to solving a wide array of mathematical problems.

Table of Contents:

• How to add Negative Fractions?
• Properties of Adding Negative Fractions
• Solved Examples
• FAQs

How to add Negative Fractions?

Grasping the Basics: Before diving into the realm of adding negative fractions, let’s revisit the fundamental principles. A negative fraction consists of a numerator (the top number) and a denominator (the bottom number), just like any other fraction. However, the negative sign (-) preceding the fraction indicates a value less than zero. Understanding the basics of fractions and their representation is crucial for successfully adding negative fractions.

Finding a Common Denominator: To add negative fractions, it is essential to have a common denominator. The common denominator allows the fractions to be combined, ensuring that the denominators are equal. If the fractions being added already have the same denominator, there is no need for further adjustments.

Adjusting the Signs: When adding negative fractions, the rule of signs is of utmost importance. If a fraction has a negative sign in front of it, it signifies a negative value. It is crucial to consider the signs while adding the fractions. Adding a negative fraction is equivalent to subtracting a positive fraction. By adjusting the signs accordingly, you can simplify the addition process.

Adding the Numerators: Once the fractions have a common denominator and the signs have been adjusted, you can add the numerators while keeping the denominator unchanged. Combine the numerators and retain the common denominator to obtain the sum of the fractions.

Simplifying the Result: After adding the fractions, it is advisable to simplify the result, if possible. Simplification involves reducing the fraction to its lowest terms by dividing both the numerator and the denominator by their greatest common factor (GCF). Simplifying the fraction ensures that it is expressed in its simplest form.

Properties of Adding Negative Fractions

Rule of Signs: The rule of signs plays a crucial role in adding negative fractions. When adding a negative fraction, it is equivalent to subtracting a positive fraction. The negative sign indicates a value less than zero, while the positive fraction represents a value greater than zero. By adjusting the signs accordingly, you can transform the addition of negative fractions into subtraction.

Finding a Common Denominator: Before adding fractions, including negative fractions, it is essential to find a common denominator. Having a common denominator allows the fractions to be combined by adding their numerators while keeping the denominator unchanged. Finding a common denominator simplifies the addition process and ensures accurate results.

Equivalent Fractions: Adding negative fractions involves making sure the fractions being added have the same denominator. In some cases, fractions may need to be converted into equivalent fractions with a common denominator. Equivalent fractions have different numerators and denominators but represent the same value. By creating equivalent fractions, the fractions can be added more easily.

Simplifying the Result: After adding the fractions, it is advisable to simplify the result if possible. Simplification involves reducing the fraction to its lowest terms by dividing both the numerator and the denominator by their greatest common factor (GCF). Simplifying the fraction ensures that it is expressed in its simplest form and provides a clear representation of the sum.

Commutative Property: The commutative property of addition applies when adding negative fractions. This property states that changing the order of the fractions being added does not affect the result. In other words, the sum of two fractions is the same regardless of their order. This property can be useful when rearranging fractions to find a common denominator or to simplify calculations.

Solved Examples

Example 1: Add: -1/4 + (-3/4)

Step 1: The fractions already have a common denominator, which is 4.

Step 2: Since both fractions are negative, there is no need to adjust the signs.

Step 3: Add the numerators while keeping the denominator unchanged.

-1/4 + (-3/4) = -4/4 = -1.

Step 4: The result, -1, is already in its simplest form, so there is no need for further simplification.

Therefore, -1/4 + (-3/4) = -1.

Example 2: Add: -2/5 + (-1/5)

Step 1: The fractions already have a common denominator, which is 5.

Step 2: Since both fractions are negative, there is no need to adjust the signs.

Step 3: Add the numerators while keeping the denominator unchanged.

-2/5 + (-1/5) = -3/5.

Step 4: The result, -3/5, is already in its simplest form, so there is no need for further simplification.

Therefore, -2/5 + (-1/5) = -3/5.

Example 3: Add: -3/8 + (-2/3)

Step 1: To add these fractions, we need to find a common denominator, which is 24 (the least common multiple of 8 and 3).

Step 2: Adjust the signs of the fractions accordingly.

-3/8 becomes -9/24 and -2/3 becomes -16/24.

Step 3: Add the adjusted numerators while keeping the denominator unchanged.

-9/24 + (-16/24) = -25/24.

Step 4: The resulting fraction, -25/24, can be simplified. Since both the numerator and denominator are divisible by 1, we can divide them by their greatest common factor, which is 1.

-25/24 ÷ 1/1 = -25/24.

Therefore, -3/8 + (-2/3) = -25/24.

Adding Negative Fractions FAQs

Grade 7 Science Worksheets

• Elements and Compounds
• Solar Energy
• Photosynthesis
• Electricity and Magnetism
• Law of conservation of energy
• Periodic table
• Properties of Matter
• Waves
• Energy Resources 
• Weather and Climate
• Immune, Circulatory and Digestive Systems
• Organs in Multi-cellular Organism
• Sedimentary, Igneous, and Metamorphic Rocks
• Structure of the Earth
• Law of Conservation of Mass
• Physical and Chemical Changes
• Scientific Method
• Human Digestive System
• Environmental Science
• Renewable and Non-renewable energy Resources
• Characteristics of Living Organisms
• Life Science
• Earth and Space Science
• Solar Eclipse
• Heat Technology
• Newton’s Laws of Motions
• Physical Science
• Tools, Measurement and SI Units
• Earth Atmosphere
• Interactions of Living things
• The Earth Ecosystem
• Organelles in Plant and Animal cells
• Layers of the Earth
• Cycles in Nature

Grade 7 Math Worksheets

• Fractions
• Linear equations word problems
• Statistics
• Properties of Parallel Line
• Finding slope from an equation
• Identifying Quadrilaterals
• Percent Change
• Properties of addition and multiplication
• Pythagorean Theorem
• Solving two step inequalities
• Symmetry
• Fractions to Decimals (New)
• Whole Number Exponents with Integer Bases (New)
• Adding and Subtracting Fractions (New)
• Integer Addition and Subtraction (New)
• Dividing Mixed Numbers (New)
• Basics of Coordinate Geometry (New)