A decimal number is simply a way of representing a number in such a way that the place value of each digit is ten times that of the digit to its right. A decimal representation does not require a decimal point.
So, for example, 437 is a number in decimal form since
It already is in decimal form.
The number is already in decimal form!
The number in decimal form is 0.12.
The number is already in decimal form!
To write 23.5 as a decimal, you can simply write it as 23.5. In decimal form, the whole number part remains the same, and the decimal part is written as it is. So, 23.5 written as a decimal is 23.5.
2.09 is a decimal.
104 is a whole number and is not usually written in a decimal form.
1.59 is already in decimal form so you do nothing!
2.346
3.0
The number 7 can be written as 7.00 in hundredths decimal form.
It is a rational number, in decimal form. In the form of a ratio, it is 11/100.