Nonnegative

Definitionadjective

What does nonnegative mean in math?

Nonnegative means greater than or equal to zero: such a number is either 0 or positive, so x ≥ 0. The nonnegative integers are 0, 1, 2, 3 and so on. It is not the same as positive, because 0 is nonnegative but not positive. Distances, absolute values and principal square roots are always nonnegative.

In Spanish
no negativo
Also called
non-negative, not negative, greater than or equal to zero, zero or positive
Grade level
6-8
Grade 6Grade 7Algebra 1SATACTGEDACCUPLACERHiSET

Nonnegative in a picture

Nonnegative versus positiveTwo number lines from -4 to 5. The top one shades x greater than or equal to 0 with a filled dot at 0; the bottom one shades x greater than 0 with an open dot at 0.Nonnegative: x ≥ 00 is included (filled dot)-4-3-2-1012345Positive: x > 00 is left out (open dot)-4-3-2-1012345The only difference is the number 0.nonnegative = positive or zero
Nonnegative and positive shade the same region; the difference is the dot at 0. Nonnegative includes 0, positive does not.

Formal definition and notation

A real number x is nonnegative if x ≥ 0, that is, if x > 0 or x = 0. The set of nonnegative real numbers is the interval [0, ∞), and the nonnegative integers are {0, 1, 2, 3, …}, the whole numbers. Similarly, nonpositive means x ≤ 0.

Symbol Read it as Meaning
x ≥ 0 x is greater than or equal to zero x is nonnegative
[0, ∞) the interval from zero to infinity, including zero all nonnegative real numbers

Key facts

  • Nonnegative = ≥ 0. Positive = > 0. The only number that is nonnegative but not positive is 0.
  • Nonnegative numbers can be fractions or decimals: 0.5 and 73 are nonnegative.
  • Always nonnegative: absolute value |x|, any square x2, the principal square root √x, distance, length and area.
  • Tests use the word to rule out negative answers: if x is nonnegative and x2 = 25, then x = 5 only.
  • For √x to be a real number, the expression under the root must be nonnegative.

Try it: x ≥ 0

Interactive

The ray shows every nonnegative number, x ≥ 0. Use the left-end button to switch the dot at 0 from closed to open: that changes nonnegative into positive.

This interactive needs JavaScript. The worked examples below show the same ideas step by step.

Nonnegative examples, step by step

Example 1: Sort the numbers

Warm-up

Which of these are nonnegative: −3, 0, 2.5, −0.1, 7?

  1. Nonnegative means ≥ 0.
  2. −3 and −0.1 are below 0, so they are out.
  3. 0 is equal to 0, so it is in; 2.5 and 7 are above 0.

Answer: The nonnegative numbers are 0, 2.5 and 7.

Example 2: When is a square root real?

Core

For which values of x is √x − 4 a real number?

  1. The expression under the root must be nonnegative: x − 4 ≥ 0.
  2. Add 4 to both sides: x ≥ 4.
  3. Check the edge: x = 4 gives √0 = 0, which is real.

Answer: √x − 4 is real exactly when x ≥ 4.

Example 3: Counting nonnegative integers

Test-style

n is a nonnegative integer and 3n − 2 < 10. How many values of n are possible?

  1. Solve: 3n < 12, so n < 4.
  2. Nonnegative integers below 4: 0, 1, 2, 3.
  3. Do not forget 0: it is nonnegative, and 3(0) − 2 = −2 < 10.

Answer: There are 4 possible values: 0, 1, 2 and 3.

Common mistakes

✗ MistakeThe nonnegative integers less than 3 are 1 and 2.
✓ InsteadThey are 0, 1 and 2.

Nonnegative includes 0. Leaving it out turns the answer into the positive integers.

✗ MistakeNonnegative and positive mean the same thing.
✓ InsteadPositive is x > 0; nonnegative is x ≥ 0. They differ only at 0.

A test that says nonnegative is telling you that 0 is allowed. That one value often changes the count or the minimum.

✗ MistakeIf x is nonnegative and x2 = 36, then x = 6 or x = −6.
✓ Insteadx = 6 only.

x2 = 36 has two solutions in general, but the condition nonnegative removes −6.

Not to be confused with

Nonnegativevs.Positive

Positive means x > 0 and excludes 0. Nonnegative means x ≥ 0 and includes 0. So 0 is nonnegative but not positive.

Nonnegativevs.Nonpositive

Nonpositive means x ≤ 0: zero or negative. Zero is the one number that is both nonnegative and nonpositive.

Nonnegativevs.Whole Number

The whole numbers 0, 1, 2, 3 and so on are exactly the nonnegative integers. Nonnegative alone also allows fractions such as 2.5.

Quick check: 3 questions

Question 1 of 3

Which number is nonnegative but NOT positive?

Show answer and explanation

Answer: D. 0 is greater than or equal to 0, so it is nonnegative, but it is not greater than 0, so it is not positive. 1 and 0.01 are both, and −1 is neither.

Question 2 of 3

x is nonnegative and |x − 2| = 5. What is x?

Show answer and explanation

Answer: B. x − 2 = 5 or x − 2 = −5, so x = 7 or x = −3. Only 7 is nonnegative. D ignores the condition, and 3 is a sign error.

Question 3 of 3

How many nonnegative integers are less than 6?

Show answer and explanation

Answer: A. 0, 1, 2, 3, 4, 5: six numbers. 5 forgets 0, 7 wrongly includes 6, and 4 drops both ends.

Nonnegative: frequently asked questions

Is zero nonnegative?

Yes. Nonnegative means greater than or equal to zero, and zero is equal to zero, so it qualifies. Zero is not positive and not negative, which is exactly why test writers use the word nonnegative: it signals that 0 is an allowed value, for example in nonnegative integers 0, 1, 2 and so on.

What is the difference between positive and nonnegative?

Positive numbers are greater than 0, written x > 0. Nonnegative numbers are greater than or equal to 0, written x ≥ 0. The two sets are identical except for the number 0, which is nonnegative but not positive. On a number line, positive uses an open dot at 0 and nonnegative a closed dot.

Are nonnegative numbers always integers?

No. Nonnegative only describes the sign. 0.75, 94 and π are all nonnegative. When a problem wants whole numbers too, it says nonnegative integer, which means one of 0, 1, 2, 3 and so on. Read both words of the phrase before you list values.

Practice and tools

Sources

  1. Weisstein, Eric W. Nonnegative. MathWorld, Wolfram Research
  2. OpenStax, Prealgebra 2e, 3.1 Introduction to Integers
  3. OpenStax, Prealgebra 2e, 5.7 Simplify and Use Square Roots

Updated November 2026·Reviewed by the Effortless Math team·Standards: n/a

Cite this entry

Effortless Math Team. “Nonnegative.” Effortless Math Dictionary. Updated November 2026. https://www.effortlessmath.com/math-dictionary/nonnegative/

Flashcard

TermNonnegativex ≥ 0
DefinitionZero or positive, never negative. 0, 3 and 2.5 are nonnegative; −1 is not. Unlike positive, it includes 0.
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