Numbers up to 2Digits
In 2digit numbers, there are only two place values  the units place and the tens place. Every number which has more than 1digit has different digits described by their place values. 2digit numbers start from 10 and end on 99. In other words, the smallest 2digit number is 10 and the greatest 2digit number is 99.
1.  What are 2Digit Numbers? 
2.  How to Write Numbers up to 2Digits? 
3.  Common Mistakes of Numbers up to 2Digits 
4.  FAQs on Numbers up to 2Digits 
What are 2Digit Numbers?
2digit numbers are the numbers that have two digits and they start from the number 10 and end on the number 99. They cannot start from zero because in that case it will be considered as a singledigit number. The digit on the tens place can be any number from 1 to 9. For example, 45, 78, 12 are twodigit numbers.
Place Value in 2 Digit Numbers
Place value is the position of each digit in a number. When we talk about 1digit numbers there is only one place value that is the ones place. When we come to 2digit numbers, there are two place values  ones and tens. Observe the following figure which shows a twodigit number 23 written along with its place values. The digit 2 is at tens place and stands for 20 and digit 3 is at ones place and stands for 3.
Assigning Place Values
We know that the place value of a number tells the position of the digit. In 2digit numbers, tens and ones are the only place values.
Let us look at the following set of numbers to understand the combination of ones and tens:
a.) 33 ⇒ 3 tens + 3 ones = (3 × 10) + (3 × 1) = 30 + 3 = 33
b.) 18 ⇒ 1 tens + 8 ones = (1 × 10) + (8 × 1) = 10 + 8 = 18
c.) 27 ⇒ 2 tens + 7 ones = (2 × 10) + (7 × 1) = 20 + 7 = 27
How to Write Numbers up to 2Digits?
2digit numbers can be written in the numeral form, in words, and in the expanded form. For example, 45 is a 2digit number. Let us see the three ways in which it can be written.
 In the numeral form: 45
 In words: FortyFive
 In the expanded form: 40 + 5
2Digit Numbers in Words
When numbers are written in words with the help of the place values, it helps us to spell them. The smallest 2digit number is 10 which is written as ten. After this, the numbers from 11 to 20 are written as 11  eleven,12  twelve, 13  thirteen, 14  fourteen, 15  fifteen, 16  sixteen, 17  seventeen, 18  eighteen, 19  nineteen, and 20  twenty. After this, they are written as 21  twentyone, 22  twentytwo, 23  twentythree, and so on till it reaches 30  thirty, and the same pattern is followed after thirty, forty, and so on.
2Digit Numbers in Expanded Form
The expanded form of a number helps to know about its constituents. The expanded form of a 2digit number can be shown in different ways. Consider a 2digit number 57.
 The number 57 can be written in one form as 57 = (5 × tens) + (7 × ones)
 In another way, it can be written as 57 = (5 × 10) + (7 × 1)
 The third way to write 57 in the expanded form is 57 = 50 + 7.
Common Mistakes of Numbers up to 2Digits
 Children can often recite all numbers up to 99 (or 100) but may make mistakes when asked to find a larger number between two numbers. They recite numbers from 1 to 100 like they have memorized the letters of the alphabet. If this happens, then finding the greater number between 14 and 15 is as puzzling as finding the greater letter between C and D. Children must realize that, unlike letters, numbers have a relationship with each other. 15 is exactly one more than 14. For this, number lines and color counters can be used to associate the sound with the quantity.
 Children tend to make mistakes working with numbers when the tens place value changes. For example, when going from 19 to 20, 29 to 30, 39 to 40, etc. Often 2digit numbers are introduced without reference to place values. While this makes it easier to memorize numbers, it may not be the best strategy as children don’t see numbers as constructed from a common set of digits from 0 to 9. In this case, an abacus can be used to model numbers and Base10 blocks can be used to help them visualize numbers.
 Children make errors in writing or reading numbers in words, especially from eleven to nineteen. There is no substitute to practice. Children must practice writing number names. Generally, with a little bit of deliberate and targeted practice, this error can be fixed easily.
Tips on Numbers up to 2Digits
Given below are some tips and tricks on numbers up to 2digits.
 When any onedigit number (from 1 to 9) multiplies by 10 the resultant number is a 2digit number. For example, 4 × 10 = 40
 The smallest 2digit number, using only one digit is 11.
 The smallest 2digit number, using two different digits is 10. (10 is the smallest twodigit number too)
 The greatest 2digit number, using only one digit is 99. (99 is the greatest twodigit number too).
 The greatest 2digit number, using all different digits is 98.
 There are only two place values in twodigit numbers, tens and ones.
 There are ninety, '2digit numbers' starting from 1099.
Here is the list of all Numbers up to 2 Digits from 1099.
Smallest 2 Digit Number
The smallest twodigit number is 10 because the previous number is 9 which is a onedigit number.
Greatest 2 Digit Number
The largest 2digit number is 99 because the next number is 100 which is a 3digit number.
Important Notes
Given below are some important notes related to numbers up to 2 digits that we studied in this article.
 The smallest 2digit number is 10 and the greatest 2digit number is 99.
 There are ninety, 2digit numbers in all.
 A 2digit number cannot start with 0, because in that case it will be considered as a singledigit number.
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Examples on 2 Digit Numbers

Example 1: What is the difference between the largest 2digit number and the number 20?
Solution: Largest 2 digit number = 99
Difference between 99 and 20 is 99  20 =79 
Example 2: Create a 2digit number in which 7 is in the tens place and 5 is in ones place. Write the number in the expanded form and write its number name.
Solution: If 7 is in tens place and 5 is in ones place, the number is 75.
The expanded form of 75 = 70 + 5. This can also be written as (7 tens) + (5 ones), or, (7 × 10) + (5 × 1)
The number name of 75 is seventyfive. 
Example 3: Write the first four '2digit numbers' and the last four '2digit numbers'.
Solution: The first four twodigit numbers are: 10, 11, 12, 13.
The last four twodigit numbers are: 96, 97, 98, 99.
FAQs on Numbers up to 2Digits
What are 2 Digit Numbers in Math?
A number is said to be a 2digit number if it consists of two digits, in which the digit on the tens place must be from 1 to 9, it cannot start from zero because in that case, it will become a singledigit number. For example, 35, 45, 60, 11, and so on are 2digit numbers.
How many TwoDigit Numbers are there?
There are ninety, 2digit numbers in all, starting from 10 and ending on 99. This means that the smallest 2digit number is 10 and the largest 2digit number is 99.
What is the Largest 2Digit Number?
The largest 2digit number is 99 as the following number is 100 which is a 3digit number.
What is the Smallest 2 Digit Number?
The smallest 2digit number is 10 because the preceding number is 9 which is a onedigit number.
What is the Biggest 2 Digit Number Divisible by 10?
The biggest 2digit number divisible by 10 is 90. Although the biggest twodigit number is 99, it is not divisible by 10.
What is the Largest 2Digit Number that can be formed with 8 and 6?
The largest 2digit number that can be formed using 8 and 6 is 86. Since 8 is greater than 6 that is why we keep 8 at tens place and 6 at ones place. Therefore, 86 is the largest twodigit number with digits 8 and 6.
Write the Expanded Form of the Given 2 Digit Number 65.
The expanded form of 65 is 60 + 5. This can also be written as, 6 tens + 5 ones, or, (6 × 10) + (5 × 1).
How many Tens are there in the 2Digit Number 20?
In the given number 20, the digit 2 is at tens place. Therefore, there are 2 tens in 20. This can be written as 20 = 2 tens + 0 ones.
Can 2 Digit Numbers Start with 0?
No, 2digit numbers cannot start with 0. The digit at tens place in a 2digit number cannot be zero, it can be any number from 1 to 9, otherwise, it will be considered as a 1digit number. For example, 05, 06, 07, are all 1digit numbers, and 56, 78, 79 are all 2digit numbers.
What are the Place Values in Numbers up to 2Digits?
Place value helps in identifying the position of digits. There are only two place values in 2digit numbers  tens and ones. For example, in the number 98, 9 is at tens place and 8 is at ones place.
Which is the Largest 2 Digit Prime Number?
The largest 2digit prime number is 97 because 97 has only 2 factors, 1 and 97.
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