Absolute Value Calculator

Calculate the absolute value of any number or expression.

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Absolute Value Calculator

Solve Equations & Inequalities

| ax + b | = c

Absolute Value

The absolute value of a number is its distance from zero on the number line, always a non-negative value. For an equation |X| = c, it splits into two possibilities: X = c and X = -c. For inequalities, |X| < c becomes -c < X < c, and |X| > c becomes X > c or X < -c.

How the Absolute Value Calculator Works

This lesson introduces a fundamental mathematical concept: absolute value. At its core, absolute value measures a number's distance from the origin (zero) on a number line, without regard to direction.

Imagine the number line is a street and you are standing at house number 0. The absolute value is simply how many houses away another house is, whether it's to your left or right. Because it represents a distance, the result is always non-negative (positive or zero).

Key Idea: Magnitude or Distance from Zero

Regardless of a number's position on the number line, its absolute value is always positive or zero. The notation for absolute value consists of two vertical bars surrounding the number or expression, such as |x|. This notation effectively removes any negative sign from the number within it, isolating its magnitude.

For any real number x, |-x| = x and |x| = x

Core Principles and Operations

Operations Within Absolute Value

When an expression is inside absolute value bars, the principle of order of operations applies. First, simplify the expression inside the bars completely. After simplifying, apply the absolute value rule to the final result.

Example: |8 - 12| = |-4| = 4

Fundamental Properties of Absolute Value

Absolute value has several key mathematical properties that are important in algebra and beyond:

  • Non-negativity: For any number 'a', |a| ≥ 0.
  • Definiteness: |a| = 0 if and only if a = 0.
  • Multiplicativity: For any numbers 'a' and 'b', |a * b| = |a| * |b|.
  • Triangle Inequality: For any numbers 'a' and 'b', |a + b| ≤ |a| + |b|.

Property in action: |-3 * 5| = |-15| = 15, and |-3| * |5| = 3 * 5 = 15.

Case Studies and Examples

Case Study: Negative Integers

Consider the integer -7. It is located seven units to the left of zero on the number line. To find its absolute value, we measure its distance from zero. The distance is 7 units.

Similarly, for the integer -25, its distance from zero is 25 units. Therefore, |-25| = 25.

Example: |-7| = 7 and |-25| = 25

Case Study: Positive Integers

Now, consider the integer 10, which is located ten units to the right of zero. The distance from zero is already a positive value, so it remains unchanged.

Likewise, the absolute value of 150 is simply 150, as it's a measure of its distance from the origin.

Example: |10| = 10 and |150| = 150

Real-World Application: Temperature and Finance

Absolute value has many practical applications. In weather, a temperature of -15°C is 15 degrees away from 0°C. In finance, a debt of $500 (represented as -$500) signifies a magnitude of $500 that is owed.

In both cases, the absolute value gives us the magnitude of the number, which is often the more relevant piece of information.

Example: |-15°C| = 15 degrees; |-$500| = $500

Visualizing on the Number Line

The absolute value represents the total units from the point of origin (zero). The visualization below shows how both negative and positive numbers measure their distance from zero.

-5
-4
-3
-2
-1
0
1
2
3
4
5
|-3| is 3 units
|4| is 4 units

Key Summary

  • Absolute value is a number's distance from zero and is always non-negative.
  • It is denoted by two vertical bars: |x|.
  • For any positive number x, |x| = x. For any negative number x, |-x| = -(-x) = x.
  • Expressions inside the bars must be simplified before the absolute value is taken.

Frequently Asked Questions