# What is the smallest 3 digit number?

The method to represent the numbers or work with numbers is known as the number system. A number system is a mathematical representation of numbers or expressing numbers. It can be also defined as the mathematical notation that is used to represent numbers of a given set by using symbols/digits. It allows operating arithmetic operations such as division, multiplication, addition, subtraction.

The most commonly used Number system is the decimal number system, the decimal referring to the use of 10 numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 to construct all the required numbers. Some important number systems are as follows,

- Decimal Number System
- Binary Number System
- Octal Number System
- Hexadecimal Number System

### What is the smallest number of three digits?

**Answer:**

The Smallest three-digit number in the number system is 100. The smallest 3 digit number in the number system is 100 because if 1 is subtracted from the number it becomes a 2 digit number which is 99 (a two-digit number). So 100 is the smallest 3 digit number in the number system.

Smallest three digit number in the number system = 100= 100 – 1

= 99 (which is a 2 digit number)

Hence it is proved that 100 is the smallest three-digit number.

**What is the smallest 3-digit number if all digits are unique?**

**Answer:**

As in the above explanation that 100 is the smallest 3 digit number in the number system. Find the smallest 3 digit number will all be unique digits. First, write the numbers which have 3-digits starting from 100 and then look for the smallest 3-digit number with all unique digits.

Thus we get,

100, 101, 102, 103, 104, 105, 106, 107…Next, find the number which has all the unique digits in it.

Explanation– In number 100, the digit 0 is repeating two times. So, 100 is not considered. Next, check for the number 101, in which 1 is repeating twice hence it is not considered. Next, consider the number 102, as no digits are repeated and it has all the 3 unique digits.

- 100 – (Digit 0 is repeating twice)
- 101 – (Digit 1 is repeating twice)
- 102 – (All digits are unique)

Thus, 102 is the smallest 3-digit number with all its unique digits.

### Similar Problems

**Question 1: What is the smallest 1 digit number?**

**Answer: **

The smallest 1 digit number in the number system is 0.

**Question 2: What is the largest 1 digit number?**

**Answer:**

Largest 1 digit number in the number system 9.

**Question 3: What is the smallest 2 digit number?**

**Answer:**

Smallest 2 digit number in the number system is 10.

**Question 4: What is the largest 2 digit number?**

**Answer:**

Largest 2 digit number in the number system 99.

**Question 5: What is the smallest 4 digit number?**

**Answer:**

The smallest 4 digit number in the number system is 1000, if 1 is subtracted from the number it becomes 3 digit number that is 999 (Three digit number). So 1000 is the smallest 4 digit number in the number system.

Smallest 4 digit number = 1000

= 1000 – 1

= 999 (Which is 3 digit number)

So it is proved 1000 is the smallest 4 digit number in the number system.

**Question 6: What is the largest 4 digit number?**

**Answer:**

The largest 4 digit number in the number system is 9999. If +1 is added to the number (9999) it becomes 5 digit number that is 10000 (a five-digit number). So 9999 is the largest 4 digit number in the number system.

Largest 4 digit number = 9999

= 9999 + 1

= 10000 (Which is 5 digit number)

So it is proved the 9999 is the largest 4 digit number in the number system.

**Question 7: What is the smallest 5 digit number?**

**Answer:**

The smallest 5 digit number in the number system is 10000, if we subtract -1 from the number it becomes 4 digit number that is 9999 (Four-digit number). So 10000 is the smallest 5 digit number in the number system.

Smallest 5 digit number = 10000

= 10000 – 1

= 9999 (Which is 4 digit number)

So it is proved the 10000 is the smallest 5 digit number in the number system.

**Question 8: What is the largest 5 digit number?**

**Answer:**

The largest 5 digit number in the number system is 99999, If 1 is added +1 to the number ( 99999 ) it becomes 5 digit number that is 100000 (Six-digit number). So 99999 is the largest 5 digit number in the number system.

Largest 5 digit number = 99999

= 99999 + 1

= 100000 (Which is 6 digit number)

So it is proved the 99999 is the largest 5 digit number in the number system.