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What is 100 - 75?
Grade Level:
Class 3
Maths, Computing, AI, Finance
Definition
What is it?
100 - 75 is a subtraction problem, where we take away 75 from 100. It helps us find the difference between these two numbers. This operation tells us how much is left when a smaller number is removed from a larger one.
Simple Example
Quick Example
Imagine you have 100 rupees in your piggy bank. You decide to buy a new cricket ball for 75 rupees. To find out how much money you have left, you would do 100 - 75.
Worked Example
Step-by-Step
Let's subtract 75 from 100 using the column method:
1. Write the numbers one below the other, aligning the ones and tens places:
100
- 75
-----
2. Start from the ones column (rightmost). We have 0 - 5. We cannot subtract 5 from 0, so we need to borrow from the tens place.
3. The tens place has 0, so we borrow from the hundreds place. The 1 in the hundreds place becomes 0, and the 0 in the tens place becomes 10.
0(10)0
- 75
-----
4. Now, from the 10 in the tens place, we borrow 1 for the ones place. So, the 10 in the tens place becomes 9, and the 0 in the ones place becomes 10.
0 9(10)
- 7 5
-----
5. Now, subtract in the ones column: 10 - 5 = 5.
0 9 10
- 7 5
-----
5
6. Next, subtract in the tens column: 9 - 7 = 2.
0 9 10
- 7 5
-----
2 5
7. Finally, in the hundreds column, we have 0 - 0 = 0 (since there's no number in the hundreds place for 75).
So, 100 - 75 = 25.
Why It Matters
Understanding subtraction is crucial for daily life and advanced studies. It's used in managing finances, calculating changes in data, and even in computer programming. Careers like financial analysts, data scientists, and engineers use subtraction constantly.
Common Mistakes
MISTAKE: Not borrowing correctly when a digit is smaller than the one below it. Forgetting to reduce the digit you borrowed from. | CORRECTION: Always remember to 'borrow' from the digit to the left, making it one less, and adding 10 to the current digit.
MISTAKE: Subtracting the smaller number from the larger number in each column, even if the larger number is below. For example, doing 5 - 0 instead of borrowing for 0 - 5. | CORRECTION: Always subtract the bottom digit from the top digit. If the top is smaller, you MUST borrow.
MISTAKE: Mixing up the order of subtraction (doing 75 - 100 instead of 100 - 75). | CORRECTION: In '100 - 75', 100 is the minuend (the number from which we subtract) and 75 is the subtrahend (the number being subtracted). Always subtract the subtrahend from the minuend.
Practice Questions
Try It Yourself
QUESTION: You scored 90 marks in a test, and your friend scored 65 marks. What is the difference in your scores? | ANSWER: 25 marks
QUESTION: A bus has 120 seats. If 85 passengers are already seated, how many seats are empty? | ANSWER: 35 seats
QUESTION: A farmer had 250 mangoes. He sold 125 mangoes in the morning and 75 mangoes in the afternoon. How many mangoes are left? | ANSWER: 50 mangoes
MCQ
Quick Quiz
What is the result of 100 minus 75?
35
25
175
75
The Correct Answer Is:
B
When you subtract 75 from 100, you are finding the difference between them. Starting with 100 and taking away 75 leaves you with 25. Options A, C, and D are incorrect results of this subtraction.
Real World Connection
In the Real World
When you check your mobile data usage, if you started with 100 GB and have used 75 GB, your phone's app does 100 - 75 to show you that you have 25 GB left. This simple subtraction helps you manage your internet plan efficiently.
Key Vocabulary
Key Terms
SUBTRACTION: Taking one number away from another to find the difference | MINUEND: The number from which another number is subtracted (e.g., 100 in 100 - 75) | SUBTRAHEND: The number that is subtracted from another number (e.g., 75 in 100 - 75) | DIFFERENCE: The result of a subtraction problem
What's Next
What to Learn Next
Great job mastering basic subtraction! Next, you can explore subtracting larger numbers with multiple borrowings. This will prepare you for more complex calculations involving money, measurements, and data.
