Auto-generate columns

[doanhquang2005]

I have an idea like this: If we set the value for the div tag = 400px:
+ If the parent element has a width of 900px, the row will have 2 div tags with a width of 450px
+ If the parent element has a width of 1200px, the row will have 3 div tags with a width of 400px
+ If the parent element has a width of 700px, the row will have 1 div tag with a width of 700px
Is there a way to write css or use bootstrap to solve the above problem?