Numbers follow a fixed order. Just like students standing in a line, every number has a place. Some numbers come before, some come after, and some come in between. When we put numbers in order, it helps us compare them and understand which is bigger or smaller.
Let us learn how to order and compare 3-digit and 4-digit numbers!
The number that comes just before a number is one less. The number that comes just after is one more. The number in between two numbers sits right in the middle.
Just before 456 is 455. Just after 456 is 457.
The number between 299 and 301 is 300.
Just before 700 is 699. Just after 999 is 1000.
Just before 1000 is 999. Just after 1000 is 1001.
The number between 2549 and 2551 is 2550.
Just before 5000 is 4999. Just after 9999 is 10000.
When we arrange numbers from the smallest to the biggest, it is called ascending order. The numbers go up like climbing stairs.
Example: Arrange 372, 158, 540, 219 in ascending order.
Answer: 158, 219, 372, 540
When we arrange numbers from the biggest to the smallest, it is called descending order. The numbers go down like coming down stairs.
Example: Arrange 805, 1230, 467, 3100 in descending order.
Answer: 3100, 1230, 805, 467
We use special signs to compare two numbers:
> means "greater than" (the bigger number is on the left).
< means "less than" (the smaller number is on the left).
= means "equal to" (both numbers are the same).
Tip: The open side of the sign always faces the bigger number. Think of it as a hungry mouth that wants to eat the bigger number!
356 > 289 (356 is greater than 289)
147 < 503 (147 is less than 503)
2450 > 1890 (2450 is greater than 1890)
600 = 600 (both are equal)
| Word | Meaning |
|---|---|
| Ascending order | Arranging numbers from smallest to biggest |
| Descending order | Arranging numbers from biggest to smallest |
| Greater than (>) | The number on the left is bigger |
| Less than (<) | The number on the left is smaller |
| Equal to (=) | Both numbers are the same |
| Skip counting | Counting forward or backward by skipping a fixed number |
A number line is a straight line with numbers placed at equal distances. Numbers increase as we move to the right and decrease as we move to the left.
On a number line: 120 ... 130 ... 140 ... 150 ... 160 ... 170 ... 180
We can see that 150 comes after 140 and before 160. Numbers on the right are always greater.
Skip counting means counting by jumping a fixed number each time.
Forward by 5: 100, 105, 110, 115, 120, 125, 130...
Forward by 10: 230, 240, 250, 260, 270, 280...
Backward by 2: 350, 348, 346, 344, 342, 340...
Backward by 100: 4500, 4400, 4300, 4200, 4100, 4000...
To form the greatest 3-digit number from given digits, arrange the digits from biggest to smallest.
To form the smallest 3-digit number from given digits, arrange the digits from smallest to biggest. If 0 is one of the digits, it cannot come first.
Digits given: 4, 7, 2
Greatest number: 742 (arrange as 7, 4, 2)
Smallest number: 247 (arrange as 2, 4, 7)
Digits given: 5, 0, 3
Greatest number: 530. Smallest number: 305 (0 cannot come first, so 3 comes first).
A. Write the Number That Comes Before, After, or Between
B. Arrange in Ascending Order
C. Arrange in Descending Order
D. Compare Using >, <, or =
E. Skip Counting -- Fill in the Missing Numbers
F. Form the Greatest and Smallest 3-Digit Number
Number Ordering Game: Your teacher will call out the roll numbers of 5 students. Write them below, then arrange them in ascending and descending order.
Roll numbers: , , , ,
Ascending order:
Descending order: