What does this statement mean?
They created 10kb bins, which could be called "dividing the genome". These are just 10kb long contiguous stretches (so position 1-10000,then 10001-20000, etc.). This is, of course, a nonsensical way of going about things, because "counting those up" in the regions you posted is the same as taking the width of the regions, dividing by 10000, and rounding a bit.

Presumably you have your markers in something like BED format, so just use bedtools to intersect them and do the counting for you.