What happens to the marginal benefit when a consumer decides to purchase an additional unit of a good, assuming the price remains constant?

When a consumer decides to buy an additional unit of a good, the marginal benefit is the extra satisfaction or value they get from that extra unit. However, as they consume more, the satisfaction from each additional unit usually decreases; this is known as diminishing marginal benefit. For example, think about eating slices of pizza. The first slice gives you a lot of enjoyment, but by the fourth or fifth slice, you may not enjoy it as much because you are starting to feel full. Therefore, even if the price stays the same, the benefit from each additional slice decreases.