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Negative Results

Overview

Going sub-zero.

What is it?

The result when a larger number is subtracted from a smaller number.

History

Brahmagupta (7th Century India) was the first to formalize rules for negative numbers, treating them as 'debt'.

Key Idea

Small - Big = Negative (Big - Small).

Practice This Topic

Concept Guide

Plain English: If you have $5 and spend $10, you don't have $0... you have -$5. You owe money. On a number line, this means going past zero into the frozen zone.

Real-world example: Overdraft fees. Temperature drops.

How to do it

  1. Recognize the Second number is bigger than the First.
  2. Swap them in your head (Big - Small).
  3. Perform the subtraction.
  4. Add a Negative sign (-) to the front of the answer.
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Common Pitfall

Thinking it's impossible. It's just negative.

Word Problem
"It is 5 degrees. The temp drops 10 degrees. What is the temp?"
Reasoning: 5 - 10. Think 10 - 5 = 5. Add negative sign. Result: -5 degrees.

Practice Examples

Debt
5 - 8 = -3
You are 3 short.