How is business donation valued?

If a business bought 2 products from China at $1 each.

Sold 1 for $10, and donate the other one to a non-profit organization.

How to calculate this business' taxable income?

$10 (revenue) - $2 (product costs) - $10 (donnated product value) = -$2?

Or

$10 - $2 = $8?

Anyone knows the correct treatment?