How to use vertical align in bootstrap

Question

Simple problem: How do I vertically align a col within a col using bootstrap? Example here (I want to vertically align child1a and child1b):

http://bootply.com/7366

Answer 1

.parent {
    display: table;
    table-layout: fixed;
}

.child {
    display:table-cell;
    vertical-align:middle;
    text-align:center;
}

table-layout: fixed prevents breaking the functionality of the col-* classes.