Percentage values in formulas. Literal number instead a %

Percentage values in formulas. Literal number instead a %

I have a percentage field (%) on a form

Scripting I copy the value of this field in a similar field (%) in a subform

The subform formulas percentage field is interpreted as a literal number : for example , 15 instead of 0.15 (15 % )

Am I doing something wrong or you need to convert the numbers in the formulas , for example : 1/15 ?