# What is the smallest 3 digit number with unique digits?

• Last Updated : 17 Aug, 2021

In our daily lives, we use numbers. They are frequently referred to as numerals. We can’t count objects, date, time, money, or anything else without numbers. These numerals are sometimes used for measurement and other times for labeling. Numbers have features that allow them to conduct arithmetic operations on them. These figures are expressed both numerically and in words. For example, 3 is written as three, 33 is written as thirty-three, and so on. To learn further, students might practice writing the numbers from 1 to 100 in words.

There are various types of numbers that we learn in Math. Natural and whole numbers, odd and even numbers, rational and irrational numbers, and so on are all examples. In this article, we’ll go through all of the different varieties. Aside from that, the numbers are utilized in a variety of applications, including number series, arithmetic tables, and so on.

A number is an arithmetic value that is used to represent and calculate a quantity. Numbers are represented by numerals, which are written symbols such as “2.”

A number system is a method of writing numbers that uses logical digits or symbols to represent them.

### Types of Numbers

The number system is a system for categorizing numbers into sets. In math, there are several different types of numbers:

• Natural Numbers: Natural numbers are positive integers from 1 to infinity that contain the positive integers 1 to infinity. The set of natural numbers is indicated by the letter “N,” and it consists of N = 1, 2, 3, 4, 5,…………
• Whole Numbers: Non-negative integers, often known as whole numbers, are non-negative integers that do not contain any fractional or decimal parts. It is symbolized by the letter “W,” and the set of whole numbers contains W = 0, 1, 2, 3, 4, 5,…………
• Integers: Integers are the set of all whole numbers, but they also include a set of negative natural numbers. Integers are represented by the letter “Z,” and the set of integers is Z = -3, -2, -1, 0, 1, 2, 3.
• Real Numbers: Real numbers are all positive and negative integers, fractional and decimal numbers that do not contain imaginary values. The letter “R” is used to signify it.
• Rational Numbers: Rational numbers are any numbers that may be expressed as a ratio of one number to another number. Any number that may be written in the form of p/q qualifies. The rational number is represented by the symbol “Q.”
• Irrational Numbers: Irrational numbers are numbers that cannot be expressed as a ratio of one to another and are denoted by the letter P.
• Complex Numbers: Complex numbers (C) are numbers that may be expressed in the form a+bi, where “a” and “b” are real numbers and I is an imaginary number.

Places in a number

If a number is 12345 then 5 is at units place, 4 is at tens place, 3 is at hundredth place, 2 is at thousand place, and so on…….
So, a number can be written as: 1*(Digit at ones place) + 10*(Digit at tens place) + 100*(Digit at hundreds place)+………………….

### What is the smallest 3 digit number with unique digits?

Solution:

Three digit numbers start from 100, 101, 102,…………. to 999.

We have to find the number with unique digits, so we can just take 1 as first digit, as a number can’t start with 0,
and to keep the number smallest we can take the 0 as second digit and as we have already used 0 and 1 as digits and we have to use unique digits so to keep the number smallest we have to use the smallest digit other than 0 and 1 i.e. 2 as third digit.
So, here the number will be 102.

### Similar Questions

Question 1: What is the smallest 4 digit number with unique digits?

Solution:

Three digit numbers start from 1000, 1001, 1002,…………. to 9999.

We have to find the number with unique digits, so we can just take 1 as first digit, as a number can’t start with 0,and to keep the number smallest we can take the 0 as second digit and as we have already used 0 and 1 as digits and we have to use unique digits so to keep the number smallest we have to use the smallest digit other than 0 and 1 i.e. 2 as third digit and similarly 3 as 4th digit. So, here the number will be 1023.

Question 2: What is the largest 3 digit number with unique digits?

Solution:

Three digit numbers start from 100, 101, 102,…………. to 999.

We have to find the largest number with unique digits, so we can just take 9 as first digit as it is the greatest digit and to keep it unique we can just take 8 and 7 as 2nd and 3rd digit respectively. So, here the number will be 987.

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