dropdown option reveals additional fields

I have a dropdown option for a Resource to add additional helpers. 

Dropdown field: " How many helpers?" the choices are 1-5. 

Depending on what number they select, is there a way for it to show that many additional fields of "Helper name" and "helper total hours"? 

So if the resource selected 2, then 2 additional fields will show so they can input the 2 helpers names and hrs worked. 

I can just add 5 additional fields for names and hrs, but if they are empty they take up too much space.