A 4-digit number is a numerical value composed of four digits, such as 1234 or 5678. These numbers can be used to represent amounts of money, serial numbers, or even telephone numbers. Understanding how to form 4-digit numbers is an important mathematical skill and can be used in everyday life. In this article, we will discuss how to form 4-digit numbers using the digits 1, 2, and 3.

## Understanding 4-Digit Numbers

A 4-digit number is composed of four distinct digits. Each of these digits can range from 0 to 9, but the digits cannot repeat. For example, the number 1234 is a 4-digit number, but the number 1134 is not. Each of the digits in the number has a place value, with the first digit being the thousands place, the second digit being the hundreds place, the third digit being the tens place, and the fourth digit being the ones place. This means that the number 1234 represents the number one thousand two hundred thirty-four.

## Forming 4-Digit Numbers with 1, 2, and 3

Using the digits 1, 2, and 3, it is possible to form a total of 24 distinct 4-digit numbers. This can be done by using all three digits in each place value, or by using the same digit multiple times. For example, one of the possible numbers is 1133, while another possible number is 1313. All of the possible numbers are listed below.

1111

1112

1113

1122

1123

1133

1211

1212

1213

1222

1223

1233

1311

1312

1313

1322

1323

1333

2111

2112

2113

2122

2123

2133

2222

Using the same digit in multiple places is a good way to form 4-digit numbers quickly. For example, using two 1s and two 2s would give the number 1122, while using two 2s and two 3s would give the number 2233.

In conclusion, forming 4-digit numbers with the digits 1, 2, and 3 is a simple task that can be done in a few steps. Understanding the place value of each digit is key to forming the correct number. With the right knowledge, forming the 24 distinct 4-

When posed with the question of how many numbers of four digits can be formed with the digits 1, 2, and 3, the answer is readily provided by the fundamental theorem of counting. According to the theorem, any finite sequence of choices, given no particular order, can be calculated by multiplying the available choices given by each decision. In the specified case, the three digits provided must each be used once, so the amount of possible choices (or numbers) can be calculated as 3 x 3 x 3 x 3: a total of 81 possible numbers.

Each of the 81 possible numbers will have only two distinct properties: the inclusion of each digit once, and the position of each digit. As the digits provided (1, 2, and 3) are consecutive, the variation in any number will then be the order in which the digits are placed, from left to right.

To give an example, the number 1234 could be calculated as a product of four separate decisions. First choosing the leftmost digit, which could be any one of the three (1, 2, or 3). This could then be followed by the decision of the second digit, and so on. As such, the number 1234 could be formed by the decision to have 1 as the leftmost digit, followed by 2 in the second place, followed by 3 in the third place, and finally 3 as the last digit.

To summarize, the number of four digits that can be formed with the digits 1, 2, and 3 is 81, due to the fundamental theorem of counting. This amount can be calculated as 3 x 3 x 3 x 3 and each number will possess the qualities of having each of the digits provided used once and the variations between each number will be the order in which the digits are placed.