What happens to marginal returns when additional units of labor are employed while keeping capital constant?

When more workers are hired while keeping the amount of equipment and tools the same, we often see something called diminishing marginal returns. This means that each new worker added produces less extra output than the worker before them. For example, if the first worker makes 10 toys in an hour, the second might only make 8 toys, and the third could make just 5. This happens because there are limited resources, like machines, to share among the workers. So, as more workers come in, they have to share the same tools, which can lead to crowded conditions and less efficiency.