How to get the total fat % in a product before you buy!

Did you know the total fat is not listed on a food label. To get this you have to do one easy and fast math problem. lol For example on a mac and cheese box, which is packaged food and junk but as an example what you do to get this info is take and if you look it says Calories from Fat are 110 (at the top right) so that would be 44% fat, wow. It does not say that anywhere, you have to do the math on that. I like to know when I buy what are the total fat from calories it does not say. frustrating. I just took the 110 and divided it into the total calories of 250 per serv on that box and it comes out to 44%. So 44 % would be the total fat in that serving of food. It does say 18 % is daily value of fat, that sounds way different which is the total of fat for the day if you eat a typical day of

 calories and fat per 2000 calories diet which is not that item of food for that serving.

I dont get it, why the labels do not show this. Has anyone else noticed this on the labels and check the fat by serving and not the daily value? They do not know how much fat I want in my day. :) So if you want the percent of fat in what you are eating you have to divide the two #;s. 110 / 250 and that is it. More the . over by two and you got it. Calories of fat is 115 divided by 250 the serv size and you get .44 and move the . over by times by 100 or just move it over 2 to the left and you get 44% of that item is fat, wow. We know mac and cheese is high fat food but what about other products when buying, so just divide the two numbers at the top: calories from fat by total calories per serving. Does anyone do this when shopping to get a picture of the fat in the product?