number Fields - What is the best way?

[bwakad]

On my template I need to have a number presented for hours per week, example:

05 - 10

40 - 40

30 - 40

12 - 13

The number on the left can be between 0 and 40

The number on the right can be maximum 40, but always - higher then / or equal to - the left number.

Obvious I can't use a page select for this.

So I thought maybe a input number should be okay. But since there has to be a "-" in between, or a word (whatever) it's difficult to do this with one field. Maybe with 2 fields, but how to connect them if 2 ?

EDIT > I was to quick, I see there was a range slider and give that a try.