Maths Playing with Numbers part 3 (Trick with 3 digit Numbers) CBSE Class 8 Mathematics VIII

TL;DR

Learn how to perform tricks with three-digit numbers by reversing, subtracting, and dividing the digits.

Transcript

hello friends this video on playing with numbers party is brought to you by example calm no more fear from example now you might be thinking that this was 2 digit number that that's why it is simplest let us deal with a three digit number so here again letters L Shalom ami three digit number so how can we represent any three digit number maybe with... Read More

Key Insights

• 🥇 Represent three-digit numbers using place value: a = 100a + 10b + c.
• ◀️ Reversing the digits of a three-digit number: bca.
• ◀️ Subtracting two reversed three-digit numbers results in a difference divisible by 99.
• #️⃣ The difference is determined by the difference between the first and last digits of the original numbers.
• 🌥️ This trick can be performed with larger numbers by dividing the difference by 9, 11, or 99.
• 🗂️ The remainder is always 0 when dividing the difference by these numbers.
• 😮 This trick can be used to impress and entertain friends by having them divide the final result.

Questions & Answers

Q: How can three-digit numbers be represented using place value?

Three-digit numbers can be written as a = 100a + 10b + c, where a is the digit in the hundreds place, b is the digit in the tens place, and c is the digit in the ones place.

Q: What happens when you reverse the digits of a three-digit number?

Reversing the digits results in the number bca, where b is the new hundreds digit, c is the new tens digit, and a is the new ones digit.

Q: What patterns emerge when subtracting two reversed three-digit numbers?

The difference between the two numbers will always be divisible by 99 and depends on the difference between the first and last digits of the original numbers.

Q: Can you give an example of using this trick with a three-digit number?

Let's take the number 873. Reversing the digits gives us 378. Subtracting these two numbers, we get 495. When divided by 9, 11, or 99, the remainder is always 0.

Summary & Key Takeaways

• The video explores representing three-digit numbers using place value and reverse digit order.

• Adding two reversed three-digit numbers does not result in any tricks, but subtracting them reveals interesting patterns.

• When subtracting, the difference between the two numbers is divisible by 99 and depends on the difference between the first and last digits.