Answer
Ca has the charge of +2.
$PO_{4}$ has the charge of -3.
$OH$ has the charge of -1.
Hence, $(+2)\times10 + (-3)\times 6 + (-1)\times 2
= 20 - 18 -2
= 0$
Work Step by Step
Ca has the charge of +2.
$PO_{4}$ has the charge of -3.
$OH$ has the charge of -1.
