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Last updated on October 14, 2025

Negative Rational Numbers

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Negative rational numbers are less than zero. They can be written as a fraction. Both the numerator and denominator are integers. The denominator is not zero. Examples include -1/2, -3/4, or -7.

Negative Rational Numbers for US Students
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What are Negative Rational Numbers?

Negative rational numbers include whole numbers, decimals, or fractions that have a negative sign (-) in front. Examples include -1/2, -4, and -3/5.

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How to Represent Negative Rational Numbers on the Number Line?

A number line is an endless line that extends infinitely on both sides. It has 0 as its center point. Numbers to the right of 0 are positive. Numbers to the left are negative. Negative rational numbers can also be represented on a number line. Let’s see how.
 

 

  • Step 1: Draw a horizontal line and mark a point in the center as 0 (zero).

 

 

  • Step 2: Mark equal intervals to the left and right of zero to represent numbers.

 

 

  • Step 3: Since we are dealing with negative rational numbers, we will focus on the left side of zero.

 

 

  • Step 4: Convert the negative rational number into its fraction or decimal form when conversion is needed.

 

 

  • Step 5: Divide the space between whole numbers into equal parts, depending on the denominator.

 

 

Example 1: Represent -3/4

 

 

  • Find the space between 0 and -1 on the number line.

 

 

  • Divide it into 4 equal parts (because the denominator is 4).

 

 

 

  • From 0 toward -1, count 3 parts and mark it as −3/4.

 

 

Example 2: Represent -1.5

 

 

  • Locate -1 and -2 on the number line.

 

 

  • Since -1.5 is halfway between -1 and -2, place a point in the middle; that’s -1.5.
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What is the Standard Form of Negative Rational Numbers?

It is a fraction that represents a number with a negative sign either in front of the fraction or in the numerator.

 

 

For example, - a/b, where a and b are positive integers.

 


You can see that the negative sign is placed in front of the fraction, which is in its lowest (simplest) form. It is important to note that the denominator is always positive.

 

 

Examples:

 

 

  • -4/6 → simplify to −2/3 → standard form

 

 

  • -6/8 → rewrite as -3/4 → standard form
     

 

  • -10/20 → simplify to -1/2 → standard form
     

 

  • -7 → can be written as -7/1 → standard form

 

 

Here, the numbers -4/6, -6/8, and -10/20 are simplified by dividing both the numerator and the denominator by their greatest common divisor (GCD). 

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Common Mistakes in Negative Rational Numbers and How to Avoid Them

Understanding negative rational numbers can be tricky for many students, especially when dealing with signs, operations, and simplification. These tips will help build confidence and accuracy in working with negative rational numbers.

Mistake 1

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Adding negative numbers incorrectly

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Students sometimes forget to keep the negative sign when adding two negative numbers. Add the absolute values and keep the negative sign. For example: \((-3) + (-2) = -5\)

Mistake 2

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Forgetting to simplify fractions

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Students leave fractions in unsimplified form. Always reduce fractions to their simplest form using the greatest common divisor (GCD).

 


For example: \(\frac{-4}{6} \) → simplified → \(\frac{-2}{3} \)

Mistake 3

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Misplacing the negative sign

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Students sometimes place the negative sign in the wrong position when writing fractions. In standard form, the negative sign should either be in front of the fraction or in the numerator.

For example: \(\text{Correct: } -\frac{2}{5} \quad \Big| \quad \text{Incorrect: } \frac{2}{-5} \rightarrow \text{rewrite as } -\frac{2}{5}\)

Mistake 4

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Confusion with subtracting negative numbers

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Students confuse subtracting a negative number with subtraction of a positive. Remember that subtracting a negative number is the same as adding a positive.

 


For example: -5 - (-2) = -5 + 2 = -3

Mistake 5

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Using the wrong order of operations

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Students forget the proper sequence when combining positive and negative numbers. Always follow the order of operations (PEMDAS/BODMAS) and handle negative signs carefully. For instance: \(-2 + 3 \times (-1) \quad \Rightarrow \quad \text{Multiply first: } 3 \times (-1) = -3 \quad \Rightarrow \quad \text{Then add: } -2 + (-3) = -5\)

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Real-Life Applications of Negative Rational Numbers

Negative rational numbers are numbers less than zero, including fractions and decimals. Learning them helps children understand mathematical concepts and build strong problem-solving skills.

 

 

  1. Temperature: In cold climates, temperatures like -10°C or -5°F are common. Negative numbers are used to represent temperatures below the freezing point.

     
  2. Elevation Below Sea Level: The Dead Sea is about -430 meters below sea level. Negative values show depth or places below the reference level.

     
  3. Stock Market Losses: If a stock drops by (-2.5%), it means the value decreased. Negative percentages show losses or decreases in value.

     
  4. Weight Change or Calorie Deficit: If someone burns more calories than they eat, the result might be a 500-calorie-per-day deficit. Used in tracking weight loss or diet deficits.

     
  5. Gaming (Losing Points or Lives): A player loses a life or 50 points; the loss of 50 points is indicated using the negative sign (-50 points).
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Solved Examples of Negative Rational Numbers

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Problem 1

The temperature was -6°C in the morning. By afternoon, it dropped 3°C. What is the new temperature?

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-9°C

Explanation

Start with the initial temperature: -6°C

It dropped 3°C → subtract 3: -6 - 3

Calculate: \(-6 - 3 = -9\)

The temperature is -9°C

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Problem 2

A submarine is 500 meters below sea level. It ascends 200 meters. What is its new depth?

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-300 meters

Explanation

Start with depth: -500 meters

Ascend 200 meters → add 200: -500 + 200

Calculate: -500 + 200 = -300

New depth: -300 meters

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Problem 3

A bank account has a balance of -$250. A deposit of $100 is made. What is the new balance?

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-$150

Explanation

The account starts with a balance of -250. A deposit of 100 is made, so we add 100 to -250.

Calculating this gives \(-250 + 100 =\) -150. So, the new balance is -$150.

 

 

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Problem 4

What is -5/6 ÷ 1/2 ?

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-5/3

Explanation

Dividing by a fraction means multiplying by its reciprocal. So, \(- \frac{5}{6} \div \frac{1}{2} = - \frac{5}{6} \times \frac{2}{1} = - \frac{10}{6} = - \frac{5}{3} \). Simplifying the fraction, we get -5/3.

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Problem 5

Which is greater - 3/4 or - 1/2 ?

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-1/2

Explanation

On the number line, numbers closer to zero are greater. Since -1/2 is closer to zero than -3/4, so it is greater

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FAQs of Negative Rational Numbers

1.What is a negative rational number?

A negative rational number can be written as a fraction. The integers make the fraction, and the integer in the denominator can never be zero. 

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2.Can a negative rational number be a decimal?

Yes, if it’s a decimal that can be written as a fraction (like -0.5 -1 /  2), then it’s a negative rational number.

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3.Is -3 a rational number?

Yes, because -3 can be written as -3  /  1, which is a ratio of two integers.

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4.Can negative rational numbers be plotted on a number line?

Yes, they appear to the left of zero on the number line.

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5.What happens when two negative rational numbers are added?

The result is another negative number with a larger negative number, like:

\(\left(-\frac{1}{2}\right) + \left(-\frac{3}{4}\right) = -\frac{5}{4} \)

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6.Are negative rational numbers different from negative integers?

Yes, negative integers are whole numbers less than zero, like: -1, -2, -3. Negative rational numbers can be fractions or decimals, like: \(-\frac{5}{2}\)  or −0.75.

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Hiralee Lalitkumar Makwana

About the Author

Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.

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Fun Fact

: She loves to read number jokes and games.

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