Yes, that is similar to SQLs group by.

Do you mean commas that are used as decimal points (done in some parts of the world, for example Germany), or commas as separators for every 10^3 step?

In the first case you might substitute the comma with a decimal point ( $num=~s/,/./;), in the second case you might remove all the commas before counting ( $num=~s/,//g; the g means global, do it to all commas, not just one)