CSS Calc() & Custom Properties

[wesamhamed]

There are mistakes in the pdf on page 7.
before:
.col-2-7{
width:calc(100%/2* 7);
}
.col-3-7{
width:calc(100%/3*7);
}
after(correct):
.col-2-7{
width:calc(100% * 2 / 7);
}
.col-3-7{
width:calc(100% * 3 / 7);
}