Increase 37 by 15% please

In order to increase a number by  15% ,
multiply it by  1.15 .

37  x  1.15  =  42.55 .

Where does the  1.15  come from ?

The ' 1 ' is the entire number that you started with,
and the  " .15 " is the additional  15%  of it.

Bis your answer rot d