What is Subtracting Two Numbers?

S0-SA1-0323

Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

Subtracting two numbers means taking one number away from another. It helps us find out how much is left or what the difference is between two quantities. When you subtract, the number gets smaller.

Simple Example

Quick Example

Imagine you have 5 delicious ladoos. If your friend eats 2 of them, how many ladoos do you have left? You take away the 2 ladoos eaten from the original 5. So, 5 minus 2 equals 3 ladoos.

Worked Example

Step-by-Step

Let's subtract 25 from 78.

Step 1: Write the numbers one below the other, aligning the ones place and tens place.
78
- 25
-----

Step 2: Start subtracting from the ones place. Subtract 5 from 8. (8 - 5 = 3)
78
- 25
-----
3

Step 3: Now, subtract from the tens place. Subtract 2 from 7. (7 - 2 = 5)
78
- 25
-----
53

So, 78 - 25 = 53.

Why It Matters

Subtracting is a basic skill used everywhere, from managing your pocket money to calculating cricket scores. It's crucial for understanding more complex math topics like algebra and problem-solving. Engineers use it to design structures, and scientists use it to analyze data.

Common Mistakes

MISTAKE: Always subtracting the smaller digit from the larger digit, even if it's in the top number | CORRECTION: Always subtract the bottom digit from the top digit. If the top digit is smaller, you need to 'borrow' from the next place value (tens, hundreds, etc.).

MISTAKE: Not aligning numbers correctly by their place value (ones under ones, tens under tens) | CORRECTION: Always make sure the digits are in the correct columns. This is very important for accurate subtraction, especially with larger numbers.

MISTAKE: Forgetting to adjust the number you borrowed from after borrowing | CORRECTION: When you borrow from a digit, remember to reduce that digit by 1 before you subtract in that column.

Practice Questions

Try It Yourself

QUESTION: What is 45 - 20? | ANSWER: 25

QUESTION: A bus started with 63 passengers. At the first stop, 15 passengers got off. How many passengers are left on the bus? | ANSWER: 48 passengers

QUESTION: Your dad bought groceries worth ₹750. He paid with a ₹1000 note. How much change should he get back? | ANSWER: ₹250

MCQ

Quick Quiz

Which of these shows the correct subtraction?

10 - 3 = 7

5 - 8 = 3

12 - 4 = 9

6 - 1 = 7

The Correct Answer Is:

Option A is correct because when you take 3 away from 10, you are left with 7. Options B, C, and D show incorrect results for subtraction.

Real World Connection

In the Real World

Every time you check your mobile data balance and see how much is left from your daily allowance, you are doing subtraction! When a shopkeeper calculates your change after you buy something, or when a cricket commentator tells you the 'runs needed' for a team to win, they are using subtraction.

Key Vocabulary

Key Terms

SUBTRACTION: The process of taking one number away from another | MINUS: A word used to mean 'take away' or 'subtract', represented by the '-' symbol | DIFFERENCE: The result you get after subtracting one number from another | BORROWING: A technique used in subtraction when a digit in the top number is smaller than the digit below it | MINUEND: The number from which another number is subtracted (the top number in a subtraction problem)

What's Next

What to Learn Next

Great job understanding subtraction! Next, you can explore 'Addition of Two Numbers' to see how numbers can be combined. You can also learn about 'Subtraction with Larger Numbers' and 'Word Problems on Subtraction' to become a subtraction expert!