coordination number

[Katherine Wu 1H]

Determine the coordination number of the metal ion in each of the following complexes:
a.[PtCl2(en)2]^2+ and b.[Cr(edta)]^+
The answer for a. is 6 (en is bidentate) and b. is 6 (EDTA is hexadentate). I don't understand how it results in six?

[kristi le 2F]

en is bidentate, meaning it has two binding sites, so each en will contribute a coordination number of 2. edta is hexadentate, so it has 6 binding sites.

[Benjamin Feng 1B]

en contributes 2 binding sites, so 2 of them create 4 bonds. That makes 6 total bonds if you include the 2 bonds from Calcium meaning it has a coordination number of 6.

[Caroline Zepecki]

if you have a coordination site and a bond inside on of those compounds, does that mean that the coordination number would be four then?