It is simply: 1215.0 but if you mean 12/15 then it is 0.8
0.1215 is a fraction. It is a fraction in decimal form rather than in the form of a ratio. However, that does not stop it being a fraction. Its rational equivalent is 1215/10000 which can be simplified. However simplification would mean that you could lose information about the precision of the fraction.
equivalent to 0.25 in decimal form = 0.250
1215 = 12150/10
Divide the percentage by 100: So 1215% = 12.15
Since 0.3 is already expressed as a decimal, there is no equivalent decimal form.
The number is already in decimal form so the equivalent decimal is 3.7
The number is already in decimal form so the equivalent decimal is 0.9
It is already in decimal form>
An equivalent decimal for 2.75 is 2.75 itself, as it is already in decimal form.
12/15 = 0.8
0.07 is in decimal form and it is equivalent to 7/100.
The decimal equivalent for 22.9 is 22.9. There is no need to convert it, as it is already in decimal form.