What is the Minus Sign?

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Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

The minus sign ( - ) is a mathematical symbol used for two main things: subtraction and showing negative numbers. It tells us to take away one quantity from another or that a number is less than zero.

Simple Example

Quick Example

Imagine you have 5 delicious laddoos. If you eat 2 of them, you use the minus sign to show how many are left: 5 - 2 = 3. This means you now have 3 laddoos.

Worked Example

Step-by-Step

Let's say your dad gave you Rs. 100 for school and you spent Rs. 40 on a new pen.
---1. Start with the initial amount of money: Rs. 100.
---2. Identify the amount spent: Rs. 40.
---3. To find out how much money is left, we use the minus sign for subtraction: 100 - 40.
---4. Perform the subtraction: 100 - 40 = 60.
---Answer: You have Rs. 60 remaining.

Why It Matters

The minus sign is fundamental in everyday calculations, from managing your pocket money to understanding temperature changes. It's crucial for careers in finance, engineering, and even game development, where precise calculations of differences and deficits are needed.

Common Mistakes

MISTAKE: Confusing the minus sign for subtraction with a negative number. For example, thinking 5 - (-2) is the same as 5 - 2. | CORRECTION: Remember that two minus signs together often mean addition (like 5 - (-2) = 5 + 2). A single minus sign before a number means it's a negative value.

MISTAKE: Forgetting to subtract when the minus sign is present. For example, seeing 7 - 3 and accidentally adding them to get 10. | CORRECTION: Always pay attention to the symbol between numbers. A minus sign means 'take away' or 'find the difference'.

MISTAKE: Incorrectly applying the minus sign when dealing with larger numbers or multiple steps. For example, in 10 - 3 - 2, doing 10 - (3-2) instead of (10-3) - 2. | CORRECTION: When multiple minus signs appear, generally work from left to right unless there are brackets. So, 10 - 3 = 7, then 7 - 2 = 5.

Practice Questions

Try It Yourself

QUESTION: Your phone had 80% battery. You watched a video that used 15% battery. How much battery is left? | ANSWER: 80 - 15 = 65%. So, 65% battery is left.

QUESTION: A shopkeeper had 120 packets of biscuits. He sold 45 packets in the morning and 30 packets in the afternoon. How many packets are left? | ANSWER: 120 - 45 = 75. Then, 75 - 30 = 45. So, 45 packets are left.

QUESTION: The temperature in Shimla was 5 degrees Celsius. Overnight, it dropped by 7 degrees Celsius. What is the new temperature? | ANSWER: 5 - 7 = -2 degrees Celsius. The new temperature is -2 degrees Celsius.

MCQ

Quick Quiz

Which of these situations correctly uses the minus sign?

Adding 5 apples to 3 apples to get 8 apples.

Finding the difference between 10 goals scored and 4 goals conceded.

Multiplying 2 by 3 to get 6.

Dividing 12 sweets among 4 friends.

The Correct Answer Is:

Option B uses the minus sign to find the difference (10 - 4 = 6). Options A, C, and D describe addition, multiplication, and division, respectively, which use different mathematical operations.

Real World Connection

In the Real World

When you check your bank balance on a UPI app like PhonePe or Google Pay, if you see a transaction with a minus sign (e.g., -Rs. 500 for a payment), it means money has been deducted from your account. Similarly, weather reports use a minus sign to show temperatures below zero, like '-2 degrees Celsius' in hill stations during winter.

Key Vocabulary

Key Terms

SUBTRACTION: The process of taking one number or quantity away from another | NEGATIVE NUMBER: A number that is less than zero, always shown with a minus sign before it | DIFFERENCE: The result of subtracting one number from another | OPERATION: A mathematical process like addition, subtraction, multiplication, or division

What's Next

What to Learn Next

Now that you understand the minus sign, you're ready to explore 'Addition and Subtraction of Integers'. This will help you work with positive and negative numbers together, which is super useful for more complex problems!