How many servings does it say it has per packet?
But, if 100g is 190 calories, then the whole packet (190*2.5) has 475 calories. Divide that in half, and you do get 237.5... (okay, you did that, I can see)....
Sometimes the labels don't make a lot of sense.... when in doubt, I'd just go with the higher calorie number.
My 5 C's of healthy living: Commitment to conscious control, with the understanding that choices have consequences