The downmods are misplaced. You're absolutely right mathwise here, you're just missing a heretofore unspoken detail. The assumption is that in an angel or VC r

The downmods are misplaced. You're absolutely right mathwise here, you're just missing a heretofore unspoken detail. The assumption is that in an angel or VC round you'll create new shares for the investor to own. If there were no new shares, pre-money valuation would always equal post-money valuation (you're just selling shares) and all of your explanation would be fine.