Solve the Subtraction Equation: 100-100 = ?

Q: Why isn't the answer 100 if I'm starting with 100?

Great question! When you subtract, you're taking away that amount. If you take away the entire amount you started with, nothing is left. Think of it like having 100 coins and giving away all 100 - you'd have zero coins remaining!

Q: Is this different from 100 + 100?

Yes, completely different! $ 100 + 100 = 200 $ (adding), but $ 100 - 100 = 0 $ (subtracting). The minus sign means you're taking away, not adding more.

Q: Does this work with any number?

Absolutely! Any number minus itself equals zero: $ 5 - 5 = 0 $, $ 73 - 73 = 0 $, even $ 1000 - 1000 = 0 $. This is a universal rule in mathematics!

Q: What if the numbers were different, like 100 - 50?

Then you'd calculate normally: $ 100 - 50 = 50 $. The zero result only happens when both numbers are exactly the same. Different numbers give different results!

Basic Subtraction with Equal Numbers

$100-100=$

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Step-by-step video solution

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00:00 Solve

00:03 Any number minus itself always equals 0

00:10 And this is the solution to the question

Step-by-step written solution

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Understand the problem

$100-100=$

Step-by-step solution

To solve this problem, we need to subtract 100 from 100 using basic arithmetic.

Step 1: Identify the operation as subtraction, $100 - 100$ .
Step 2: Apply the arithmetic property: Subtract any number from itself, and the result is $0$ .
Step 3: Calculate: $100 - 100 = 0$ .

Subtracting the number from itself means we are finding the difference between two equal numbers, which is always zero.

Therefore, the result of subtracting 100 from 100 is $\mathbf{0}$ .

Final Answer

Key Points to Remember

Essential concepts to master this topic

Rule: Any number subtracted from itself always equals zero
Technique: When identical numbers are subtracted: $100 - 100 = 0$
Check: Add the difference back to the second number: $0 + 100 = 100$ ✓

Common Mistakes

Avoid these frequent errors

Thinking the answer is the original number
Don't assume $100 - 100 = 100$ just because 100 appears twice! This means you're not actually subtracting. Always remember that taking away the full amount leaves nothing behind, which is zero.

Practice Quiz

Test your knowledge with interactive questions

$1\times1000=$

FAQ

Everything you need to know about this question

Why isn't the answer 100 if I'm starting with 100?

Great question! When you subtract, you're taking away that amount. If you take away the entire amount you started with, nothing is left. Think of it like having 100 coins and giving away all 100 - you'd have zero coins remaining!

Is this different from 100 + 100?

Yes, completely different! $100 + 100 = 200$ (adding), but $100 - 100 = 0$ (subtracting). The minus sign means you're taking away, not adding more.

Does this work with any number?

Absolutely! Any number minus itself equals zero: $5 - 5 = 0$ , $73 - 73 = 0$ , even $1000 - 1000 = 0$ . This is a universal rule in mathematics!

How can I remember this rule?

Think of real-life examples: If you have 100 dollars and spend all 100 dollars, you have zero dollars left. Or if you eat 5 cookies out of 5 cookies, there are zero cookies remaining!

What if the numbers were different, like 100 - 50?

Then you'd calculate normally: $100 - 50 = 50$ . The zero result only happens when both numbers are exactly the same. Different numbers give different results!

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