About Negative Numbers in Daily Life
What are Negative Numbers?
Negative numbers are numbers with a value that is less than zero. These numbers are represented with a minus sign (-) before them. On a number line, negative numbers appear on the left side of the zero. For example, -5, -2 and -56 are negative numbers.
How are Negative Numbers useful in daily life?
Every number has an equal amount of responsibility to let us know the count or a measure of a quantity. The same goes for zero and negative numbers. Negative numbers are used in various situations in daily life. Here are some of the instances where negative numbers are required.
- For expressing temperatures – Negative numbers are used in expressing weather conditions. For example, when the temperature in cold regions falls below zero degrees, we express the temperature as -15˚C or on the Fahrenheit scale this will be 59˚F.
- For monetary purposes – In the banking system, negative numbers are used for showing credit. When the bank statement shows a negative number, it means that the account has been overdrawn and there is a negative balance.
- Surface water level – Sea level is considered as an average level of Earth’s oceans. As a result, the surface water level becomes the benchmark and numbers below the sea level will be negative numbers.
- Tests and games – There are negative marks as penalty for tests and games. A wrong answer leads to a reduction of the result that eventually can become a negative number.
Solved Examples
Example 1: The temperature in a particularly cold city was 17˚ F during the day and dropped to 5˚F at night. What will happen if the temperature drops further by 7˚ F at midnight?
Solution:
Temperature during the day = 17˚ F
Temperature at night = 5˚ F
Now, if the room temperature drops further, then, we will get a negative number as a result.
We can see this in the following equation.
5 – 7 = -2
Hence, the temperature in the city dropped to -2˚ F at midnight.
Example 2: Find the predecessor of these following numbers:
- -12
- -45
- 0
Solution:
The term ‘predecessor’ is used for the number that comes before a specific number.
In order to find the predecessor of any number, we have to subtract 1 from the number.
- Predecessor of -12 is -12 – 1 = -13
- Predecessor of -45 is -45 – 1 = -46
- Predecessor of 0 is 0 – 1 = -1
Example 3: Melissa attended a school test in which every correct answer is worth +4 points and an incorrect answer is -2 points. Out of 25 questions, Melisa got 15 correct and 10 incorrect answers. What is Melissa’s total score?
Solution:
As stated, every correct answer will be +4 points and incorrect answers will be -2 points.
Since Melissa answered 15 questions correctly, the total score is 15 x 4 = 60 points.
Now, Melissa has got 10 incorrect answers as well. For every incorrect answer, she will get -2 points.
So, she has got total incorrect score of 10 x -2 = -20 points.
Now, the total points earned by Melissa in her test is,
60 + (-20) = 60 – 20 = 40 points
Hence, Melissa scored a total of 40 points in her school test.
The temperature of Fairbanks, a city in Alaska, can be around -16˚ F and can go as low as -60˚ F.
Yes, real numbers can be both negative and positive. -3, -2, -1, 1, 2, 3 are examples of real numbers.
Integers are numbers without any decimal or fractional part. Integers include both negative and positive numbers along with 0.