5-digit numbers (Basic Concepts)

Welcome to the World of Big Numbers!

Hi there! So far, you have learned about numbers up to 1,000 and even 4-digit numbers. But did you know that numbers can get much, much bigger? In this chapter, we are going to explore 5-digit numbers. These are numbers that go all the way up to 99,999!

Learning 5-digit numbers is like getting a superpower for your brain. It helps you understand things like the price of a fancy laptop, the number of people in a big stadium, or how far a car travels in a year. Don't worry if it looks like a lot of digits at first—we will break it down step-by-step!

1. Understanding the Ten Thousands Place

When we add one more digit to a 4-digit number, we move into a new "house" called the Ten Thousands place.

Before we start, let's do a quick review of the places we already know:

1. Units (like 1)
2. Tens (like 10)
3. Hundreds (like 100)
4. Thousands (like 1,000)
5. Ten Thousands (the new one! Like 10,000)

The Place Value Chart

Imagine a row of 5 boxes. Each box has a specific value:

[Ten Thousands] [Thousands] [Hundreds] [Tens] [Units]

For example, in the number 24,561:
- The 2 is in the Ten Thousands place (it stands for 20,000).
- The 4 is in the Thousands place (it stands for 4,000).
- The 5 is in the Hundreds place (it stands for 500).
- The 6 is in the Tens place (it stands for 60).
- The 1 is in the Units place (it stands for 1).

Did you know?

The smallest 5-digit number is 10,000 (ten thousand), and the largest is 99,999 (ninety-nine thousand nine hundred and ninety-nine).

Key Takeaway: A 5-digit number always has a Ten Thousands place. It tells us how many "ten thousands" are in the number.

2. How to Read and Write 5-Digit Numbers

Reading big numbers is easy if you use the "Thousands Bridge" trick.

The "Thousands Bridge" Trick

To read a 5-digit number, look at the first two digits together. These are your "thousands." Say them first, then say the word "thousand," and then read the rest of the number normally.

Example: Read 53,208
1. Look at the first two digits: 53. Say "Fifty-three."
2. Add the word "thousand": "Fifty-three thousand."
3. Read the rest: "two hundred and eight."
4. Put it together: Fifty-three thousand, two hundred and eight.

Quick Review: Writing in Words

Try writing these down:
- \(30,000\) = Thirty thousand
- \(12,450\) = Twelve thousand, four hundred and fifty
- \(60,007\) = Sixty thousand and seven (Notice how we say "and" if there are zeros in the middle!)

Key Takeaway: Always group the first two digits together and say "thousand" after them.

3. Counting Onwards and Backwards

Counting with 5-digit numbers is just like counting with smaller numbers, but the numbers look longer! You can count by 1s, 10s, 100s, or even 1,000s.

Counting Onwards (Going Up)

When you count onwards, the number gets bigger.
Example (Counting by 1,000s):
12,000 → 13,000 → 14,000 → 15,000

Counting Backwards (Going Down)

When you count backwards, the number gets smaller.
Example (Counting by 10s):
20,050 → 20,040 → 20,030 → 20,020

Watch out for "The Big Change"!

Don't worry if this seems tricky at first: when you are at a "9", the next number will change the digit to its left.
Example: What comes after 19,999?
The next number is 20,000!

Key Takeaway: Look closely at which "place" is changing (the units, tens, hundreds, etc.) to keep your counting steady.

4. Odd and Even 5-Digit Numbers

Here is a secret: No matter how big a number is, only one digit matters when deciding if it is Odd or Even. That is the digit in the Units place (the very last digit on the right)!

- Even Numbers end in: 0, 2, 4, 6, or 8.
- Odd Numbers end in: 1, 3, 5, 7, or 9.

Example:
- 45,672 is Even because it ends in 2.
- 89,007 is Odd because it ends in 7.

Key Takeaway: Ignore the "Ten Thousands" or "Thousands"—just look at the very last digit to find out if it is odd or even!

5. Comparing the Magnitude (Which is Bigger?)

When we compare two 5-digit numbers to see which is larger or smaller, we always start looking from the left side (the biggest place value).

Step-by-Step Comparison:

1. Look at the Ten Thousands place first.
2. If those digits are the same, move to the Thousands place.
3. If those are the same, move to the Hundreds place... and so on.

Example: Which is bigger, 34,500 or 32,999?
- Ten Thousands: Both have 3. (It's a tie!)
- Thousands: One has 4, the other has 2.
- Since 4 is bigger than 2, then 34,500 is greater than 32,999.

Common Mistake to Avoid:

Don't be fooled by big digits at the end! Even though 32,999 has lots of 9s, the Thousands place (the 4 in 34,500) is much more important.

Key Takeaway: Start from the left! The first digit that is different tells you which number is larger.

Quick Review Quiz

1. In the number 76,432, which digit is in the Ten Thousands place? (Answer: 7)
2. Is 10,001 an Odd or Even number? (Answer: Odd, it ends in 1)
3. What is 1,000 more than 48,500? (Answer: 49,500)
4. Which is smaller: 55,010 or 55,100? (Answer: 55,010)

You are doing great! Keep practicing and these big numbers will feel like small ones in no time!