What is Taking Away One Hundred?

S0-SA1-0783

Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

Taking away one hundred means reducing a number by exactly 100. It's a basic subtraction operation where the value of 100 is removed from a larger number. This helps us find out how much is left after a specific amount is subtracted.

Simple Example

Quick Example

Imagine you have 350 rupees saved for a new cricket bat. If you spend 100 rupees on a new cricket ball, how much money do you have left? You take away 100 from 350, which leaves you with 250 rupees.

Worked Example

Step-by-Step

Let's say a school library has 785 storybooks. If 100 books are borrowed by students for a reading competition, how many books are still in the library?

Step 1: Start with the total number of books: 785.
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Step 2: Identify the amount to be taken away: 100.
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Step 3: Set up the subtraction problem: 785 - 100.
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Step 4: Subtract the ones place: 5 - 0 = 5.
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Step 5: Subtract the tens place: 8 - 0 = 8.
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Step 6: Subtract the hundreds place: 7 - 1 = 6.
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Step 7: Combine the results. The remaining number is 685.

Answer: There are 685 books left in the library.

Why It Matters

Understanding how to take away 100 is crucial for everyday calculations, from managing your pocket money to understanding discounts. It's a foundational skill for careers like accounting, retail management, and even in fields like data analysis where you track changes in quantities.

Common Mistakes

MISTAKE: Students sometimes subtract from the wrong place value, like subtracting 1 from the tens place instead of the hundreds place. For example, 545 - 100 = 544. | CORRECTION: Remember that 100 has a '1' in the hundreds place, so it affects only the hundreds digit of the number you are subtracting from.

MISTAKE: Forgetting to subtract from all relevant digits when the number is smaller than 100 in its hundreds digit, leading to errors like 150 - 100 = 150 (no change). | CORRECTION: Always perform subtraction across all place values. If the hundreds digit becomes 0, that's fine (e.g., 150 - 100 = 50).

MISTAKE: Confusing 'taking away 100' with 'taking away 10' or 'taking away 1'. For example, 480 - 100 = 470. | CORRECTION: Pay close attention to the number you are subtracting. 'One Hundred' means 100, not 10 or 1. Each has a different impact on the number.

Practice Questions

Try It Yourself

QUESTION: A mobile phone plan gives you 875 MB of data. If you use 100 MB for watching videos, how much data is left? | ANSWER: 775 MB

QUESTION: A shopkeeper had 234 packets of biscuits. He sold 100 packets. How many biscuit packets does he have now? | ANSWER: 134 packets

QUESTION: Your school auditorium has 999 seats. For a special event, 100 seats were reserved for teachers and staff. How many seats are available for students? | ANSWER: 899 seats

MCQ

Quick Quiz

What is 625 minus 100?

624

525

615

524

The Correct Answer Is:

When you subtract 100 from 625, only the hundreds digit changes. 6 minus 1 equals 5, so the new number is 525. The tens and ones digits remain the same.

Real World Connection

In the Real World

When you check your bank balance on a UPI app like PhonePe or Google Pay, and you transfer 100 rupees to a friend, the app instantly shows your new balance after 'taking away 100' from your total. This basic subtraction is happening behind the scenes.

Key Vocabulary

Key Terms

SUBTRACTION: The process of taking one number or amount away from another. | DIFFERENCE: The result of subtracting one number from another. | PLACE VALUE: The value of each digit in a number based on its position. | MINUS: A symbol (-) indicating subtraction.

What's Next

What to Learn Next

Next, you should learn about 'Taking Away Any Three-Digit Number'. This builds on 'taking away 100' by applying the same principles to subtract any number with hundreds, tens, and ones, making your subtraction skills even stronger!