Fair points, so let me explain my reasoning there:<p>First of all, in the case from my past, the machine labeled it -- &quot;mmHg&quot;.  They could have read it off, had they expected things to have units that matter.<p>Second, it&#x27;s part of the conceptual understanding of what blood pressure <i>means</i> -- that e.g. it&#x27;s not some normalized percentage, that it indicates how much the fluid inside is pressing against the outside, that it&#x27;s relative to atmospheric pressure, that we live in and expect a pressurized environment.<p>Third -- I mean, you read it out every day, wouldn&#x27;t you ever wonder what it means? Imagine a Java dev that doesn&#x27;t know what System is, only that it&#x27;s the beginning of the stdout print statements they use.<p>Someone who merely knows that &quot;180 bad, 120 good&quot; has a disconnected understanding, like the expert who can literally do nothing more than plug numbers into an equation but not know what the numbers mean or whether you&#x27;re measuring them correctly to be compatible with it. It&#x27;s not enough.