What are Odd Numbers?
Odd numbers are those numbers that are not completely divisible by 2. The fact is that there is always a remainder when an odd number is divided by 2. The last digit of an odd number is 1, 3, 5, 7, or 9. The set of odd numbers comprises 1, 3, 5, 7, 9, 11, 13, 15, and so on.
An odd number can also be defined in terms of whether it can be divided into two equal parts or not. This is linked to the fact that odd numbers cannot be divided into two equal parts.
For example, 7 = 5 + 2 or 4 + 3, in both cases, the numbers being added are not equal to each other, hence, showing us that 7 is not divided into two equal parts.
How do we know that a Number is Even or Odd?
Any even number can be to be a sum of two equal numbers or two equal values, while any odd number cannot be shown as the sum of two values or two equal parts.
In the above image, the blocks are in equal parts. Hence, it shows an even number which is ‘8’.
The above figure shows an unequal distribution of blocks. Hence, it shows an odd number of ‘7’.
Listing the odd numbers Between 1 to 100
The table here lists the odd numbers between 1 to 100.
Solved Examples
Example 1: In the following model, identify whether the number of blocks represents an even or an odd number.
Solution:
In the model, there are two parts. While one model has 4 cubes, the second model has 3 cubes.
This shows that the two parts are not equal.
The total number of cubes is 4 + 3 = 7
Hence, the number represented by the model is 7, which is an odd number.
Example 2: There is an odd number of notebooks on Amy’s desk. There are more than 17 notebooks but less than 21 notebooks on the desk. How many notebooks are there on the desk?
Solution:
From the problem, there are more than 17 notebooks but fewer than 21 notebooks.
Check the chart of odd numbers, to find the odd number that appears after 17 and before 21.
19 is the odd number that appears after 17 and before 21.
Hence, there are 19 notebooks on Amy’s desk.
Example 3: Melanie has 23 dresses that she wants to distribute between two of her friends. Do you think she can divide the number of dresses equally?
Solution:
The number of dresses Melanie has = 23
23 is an odd number and it cannot be divided equally.
Hence, Melanie cannot give her two friends an equal number of dresses to her two friends, as 23 is an odd number.
The number 22 is not an odd, but an even number. 22 is perfectly divisible by 2 without leaving any remainder, and it can be divided into two equal parts as well, that is, 11 + 11 = 22.
The number 3 is the smallest odd prime number.
The count of odd numbers is not limited to 100 but the list is endless, hence the count is endless as well.
Yes, 57 is an odd number as it’s not perfectly divisible by 2. The last digit of 57 is 7, which is an odd number and the number cannot be equally divided into two equal parts.