It looks like you have the operands out of order.

Change "=+" to "+=" and it should owrk just fine.

Your code:

double myNumber = 0;

if (myNumber < .15){
myNumber =+ .0001;
}else{
myNumber = .04;
}

Should read:
double myNumber = 0;

if (myNumber < .15){
myNumber += .0001;
}else{
myNumber = .04;
}