Integer
- CBSE · NCERT Class 6, Ch 10 The Other Side of Zero
An integer is a whole number or its negative, so the integers are ..., -3, -2, -1, 0, 1, 2, 3 and so on in both directions.
Integers are the numbers on both sides of zero. The positive integers are 1, 2, 3 and upward. The negative integers are -1, -2, -3 and downward. Zero is an integer too, but it is neither positive nor negative.
They are handy wherever things go below a starting point: a lift going under the ground floor, a temperature below freezing, or money owed. An integer has no fraction or decimal part.
A small example
The temperature at night is -4 °C. By noon it has risen 9 degrees. The new temperature is -4 + 9 = 5 °C.
Subtracting a negative works the other way. 6 - (-2) means taking away a debt of 2, which leaves you 2 better off. So 6 - (-2) = 6 + 2 = 8.
Which of 7, -12, 0.5 and 0 are integers? 7, -12 and 0 are. 0.5 is not, because it has a decimal part.
Why it matters later
A rational number is defined using integers: p/q, where p and q are integers and q is not 0. In Class 10 Chapter 1, the proof that a number is irrational starts from that form. The words "where a and b are integers" are part of the answer the examiner expects.
Sources
Facts last checked against these sources on 30 September 2026.
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