Either because verbal communication is a "holdover" from the Apollo era, or because it is the safest way to confirm everything is correct. We place a lot of tr

Either because verbal communication is a "holdover" from the Apollo era, or because it is the safest way to confirm everything is correct. We place a lot of trust in our computers...but when a single typo can mean life or death I think I'd prefer to verbally confirm the number too.