In which part of the circulatory system does the exchange of oxygen and dioxide take place between blood and cells?

The exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.

Amount/total x 100

First of all, you find the total amount of grams in the dessert

In this case you want to find the % of calories coming from fat.

So you would divide the number of grams of fat by the total amount of grams in the dessert

And then you would multiply the answer by 100.