Final answer:
Positive and negative numbers are used in real life to represent a variety of conditions such as bank accounts, temperature scales, elevations, golf scores, and electrical circuits. Multiplication and division involving these numbers follow specific rules regarding the sign of the outcome.
Step-by-step explanation:
Understanding positive and negative numbers in real life is crucial for solving everyday problems. Here are five examples that illustrate how these numbers can be applied:
- Bank accounts: If your bank account has a positive balance, you have that amount of money available. Conversely, a negative balance indicates an overdraft, meaning you owe money to the bank.
- Temperature scales: Temperatures above zero are positive, representing heat. Temperatures below zero are negative, representing cold. This is especially relevant in regions with cold climates where temperatures can fall below freezing.
- Elevations: Sea level is considered the zero point. Elevations above sea level (+ve) are positive, and elevations below sea level (−ve) are negative. This can affect climate, air pressure, and travel.
- Golf scores: Scores in golf are often given in relation to par. Scoring less than par (−ve) is good, as it means the player took fewer strokes, while scoring more than par (+ve) indicates more strokes were taken.
- Batteries and Electrical Circuits: In electrical circuits, positive (+ve) and negative (−ve) charges have different roles. The flow of current goes from the positive to negative terminal of a battery.
When we talk about multiplying and dividing these numbers, the rules are straightforward. For instance, when two positive numbers multiply, like 2x3, the result is also positive. Similarly, when two negative numbers like (-4) x (-3) are multiplied, the outcome is positive as well. However, if the numbers have opposite signs, such as (-3) x 2, the result will be negative. This concept also applies to division—the signs follow the same rules as multiplication.