What is the Inequality Sign (< and >)?

S1-SA5-0589

Grade Level:

Class 4

Maths, Computing, AI, Logic

Definition

What is it?

Inequality signs are special symbols used in Maths to show that two numbers or expressions are not equal. The two main inequality signs are '<' (less than) and '>' (greater than). They help us compare values and understand which one is bigger or smaller.

Simple Example

Quick Example

Imagine your friend scored 85 marks in Science, and you scored 90 marks. To show that your score is more than your friend's score, we can use the greater than sign: 90 > 85. This means 90 is greater than 85.

Worked Example

Step-by-Step

Let's compare the number of ladoos in two boxes. Box A has 12 ladoos and Box B has 15 ladoos. Which box has fewer ladoos? Which box has more ladoos? Let's use inequality signs to show this.

Step 1: Identify the two numbers to compare. They are 12 and 15.
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Step 2: Think about which number is smaller. 12 is smaller than 15.
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Step 3: To show that 12 is less than 15, we use the '<' sign. The sign 'points' to the smaller number. So, we write 12 < 15.
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Step 4: Now, think about which number is larger. 15 is larger than 12.
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Step 5: To show that 15 is greater than 12, we use the '>' sign. The 'open mouth' of the sign faces the larger number. So, we write 15 > 12.
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Answer: 12 < 15 and 15 > 12.

Why It Matters

Understanding inequality signs is super important for logical thinking, which is key in Computing and AI. Engineers use them to set conditions for programs, like 'if temperature > 30 degrees, turn on AC'. Data scientists use them to compare data, helping make smart decisions in fields like finance and sports analytics.

Common Mistakes

MISTAKE: Confusing the '<' and '>' signs, always thinking the sign opens to the right. | CORRECTION: Remember the 'Alligator Mouth' rule: the open side of the sign always 'eats' the larger number. The pointed tip always faces the smaller number.

MISTAKE: Using the equals sign (=) when numbers are not exactly the same. | CORRECTION: Only use '=' when the two values are exactly identical. For any difference, no matter how small, use '<' or '>'.

MISTAKE: Not understanding that the inequality sign works the same way even if the numbers are swapped (e.g., 5 < 10 and 10 > 5 are the same idea). | CORRECTION: Both statements mean the same thing: 5 is less than 10. The sign just changes direction depending on which number you write first.

Practice Questions

Try It Yourself

QUESTION: Fill in the blank with < or >: 23 ___ 18 | ANSWER: 23 > 18

QUESTION: Is the statement '45 < 39' true or false? | ANSWER: False

QUESTION: Your mobile data plan gives you 2 GB per day. If you have used 1.5 GB today, do you have more or less than 1 GB remaining? Write it using an inequality sign. | ANSWER: You have 0.5 GB remaining. So, 0.5 GB < 1 GB.

MCQ

Quick Quiz

Which statement correctly compares the price of a small chai (Rs. 10) and a large chai (Rs. 15)?

10 > 15

15 < 10

10 < 15

10 = 15

The Correct Answer Is:

Option C, '10 < 15', correctly shows that the price of a small chai (10 rupees) is less than the price of a large chai (15 rupees). The other options are incorrect comparisons.

Real World Connection

In the Real World

When you buy groceries online using apps like Swiggy Instamart or Blinkit, the app often compares prices of different items or checks if your total bill is greater than the minimum order value for free delivery. These apps use inequality logic to display offers or apply discounts, helping you save money!

Key Vocabulary

Key Terms

INEQUALITY: A mathematical statement showing that two expressions are not equal | LESS THAN (<): Used when the first number is smaller than the second | GREATER THAN (>): Used when the first number is larger than the second | COMPARE: To check how two or more things are similar or different | VALUE: The numerical amount of something

What's Next

What to Learn Next

Great job learning about inequality signs! Next, you can explore 'Comparing Numbers with Decimals' or 'Ordering Numbers from Smallest to Largest'. These concepts will build on your understanding of inequalities to compare more complex numbers and arrange them logically.