In demand theory, we can treat "benefit" approximately as "utility" expressed in money terms. As usual, we will be interested in the marginal benefit. We can define the marginal benefit in parallel as we did the marginal utility: the marginal benefit from burgers is the increase in total benefit as a result of consuming one more burger (per week). In algebraic terms:
That is, as near as we can approximate, the marginal benefit is the additional benefit from increasing consumption by one unit. For example, using the table in the previous overhead, when consumption of burgers is increased from 2 burgers to 4, we have 
total benefit = 18-15 = 3 and burgers = 4-2 = 2, so the marginal benefit for the range of 2 to 4 burgers is 3/2=1.5.
Dollars of "benefit" parallel "utility" in another way: marginal benefit declines with increasing consumption of a good, ceteris paribus. We will see that the marginal benefit of burgers is smaller, in our example, the more burgers the consumer has. Here is the information we need in a table. We'll compute the marginal benefit from the total benefit using the definition and formula above.
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