Negative Number Subtraction

In the realm of mathematics, negative numbers often pose a challenge for many students. However, understanding how to subtract negative numbers is a crucial skill that opens up a world of possibilities in mathematics and real-life scenarios.

Subtracting negative numbers may seem daunting at first, but with a clear understanding of the concepts and a few helpful techniques, it becomes an achievable task.

In this section, we will delve into the realm of negative number subtraction, specifically designed to assist Grade 7 students in mastering this operation.

Understanding the Basics:

To subtract negative numbers, it is essential to grasp the fundamental concept that subtracting a negative is equivalent to adding a positive. This concept forms the basis for subtracting negative numbers and allows us to simplify complex problems into more manageable calculations.

Working with Signs: When subtracting negative numbers, attention to signs is crucial. Here are some key rules to remember:

Subtracting a Negative Number: Subtraction is transformed into addition when a negative number is involved. For example, subtracting -5 is the same as adding 5. This simplification helps in performing the subtraction accurately.

Double Negatives: A double negative cancels out and becomes a positive. For instance, subtracting -7 is equivalent to adding 7. This rule clarifies the concept that subtracting a negative number results in a positive value.

Strategies for Subtraction:

To subtract negative numbers effectively, consider employing these strategies:

Visualization with Number Line:

Utilize a number line to visualize the subtraction process. Starting from the initial number, move in the opposite direction based on the value of the negative number being subtracted. This visualization aids in understanding the concept of subtracting a negative.

Changing to Addition:

To simplify subtraction, reframe the problem as an addition by changing the subtraction sign to addition. For example, instead of subtracting -9, add 9 to the given number. This strategy simplifies the calculation and eliminates the negative sign.

Applying Absolute Value:

Convert negative numbers to their positive counterparts (absolute values) before performing subtraction. By removing the negative sign, the problem becomes a straightforward subtraction. For instance, subtracting -4 can be rewritten as subtracting 4.

Practice and Reinforcement:

Engage in ample practice exercises to reinforce the concepts and techniques of negative number subtraction. Work through a variety of problems that involve negative numbers to enhance understanding and build confidence.

Formulas with Examples

Subtraction Rule:

To subtract two numbers, a and b, where one or both numbers are negative, you can rewrite the subtraction as addition by changing the sign of the number being subtracted:

a – b = a + (-b)

Example 1:

Subtract -5 from 2:

2 – (-5) = 2 + 5

2 – (-5) = 2 + 5 = 7

Example 2:

Subtract -8 from -3:

-3 – (-8) = -3 + 8

-3 – (-8) = -3 + 8 = 5

Rule of Subtracting a Negative:

The subtraction of a negative number is equivalent to addition. When subtracting a negative number, change the operation to addition and change the sign of the negative number to positive:

a – (-b) = a + b

Example 3:

Subtract -7 from 4:

4 – (-7) = 4 + 7

4 – (-7) = 4 + 7 = 11

Example 4:

Subtract -2 from -9:

-9 – (-2) = -9 + 2

-9 – (-2) = -9 + 2 = -7

Double Negative Rule:

Two negative signs in succession cancel each other out and become positive:

-(-a) = a

Example 5:

Simplify -(-6):

-(-6) = 6

Example 6:

Simplify -(-3):

-(-3) = 3

By applying these formulas and rules, Grade 7 students can effectively subtract negative numbers. It’s important to remember the properties of negative numbers and practice solving a variety of examples to strengthen understanding. With practice, students can confidently handle negative number subtraction and build a solid foundation for more advanced mathematical concepts.

Real-life Applications

Temperature:

Negative numbers are commonly used to represent temperatures below zero. In regions with cold climates, temperatures often drop below freezing, leading to negative temperatures. Weather forecasts, thermometers, and climate studies frequently involve negative numbers to measure and compare temperatures accurately.

Banking and Finance:

Negative numbers are crucial in financial transactions and accounting. They represent debts, withdrawals, or losses. Bank accounts can have negative balances when expenses exceed income or when loans are taken. Negative numbers help track and calculate financial obligations, allowing individuals and businesses to manage their finances effectively.

Elevation and Altitude:

Negative numbers are used to indicate elevations or altitudes below a reference point. For example, when measuring the depth of a body of water or the height of a location below sea level, negative numbers are employed to denote positions below the established baseline.

Sports Statistics:

Negative numbers are often used in sports statistics to indicate a decrease in performance or a loss of points. In sports like basketball or football, scores can have negative values when penalties or deductions are applied to a team’s total points. Negative numbers help track and analyze performance within the context of the game.

Stock Market:

Negative numbers are significant in the stock market. They represent a decrease in stock prices or financial losses. Stock market indices and financial charts frequently include negative numbers to indicate declines in value or negative returns on investments.

GPS and Navigation:

GPS (Global Positioning System) and navigation systems use negative numbers to represent coordinates and locations in different quadrants. Negative latitude and longitude values help pinpoint precise locations on Earth’s surface, facilitating accurate navigation and mapping.

Negative Number Subtraction 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)