It should always be meters, Asia uses meters. But what Exif viewer are you using? (rhetorical). The /10 numbers are always a property of the viewer not getting concept quite right.
I would strongly suggest any serious user as yourself should get the free ExifTool viewer. One way it is unique is because it is updated a couple times a month. Most others are years old, and obsolete, because Nikon changes the Manufacturers format now and then. This is how Adobe gets by about forcing updates for each new camera model. Raw only needs it to try to get white balance, but updates seem a good idea to them.
Note at first glance, ExifTool is a command line viewer, but there is also a nifty free Windows tool that converts it to a full GUI Windows app (see
Camera Exif data - ExifTool for details).
Even so, the subject distance in a zoom lens is far from trustworthy, the extreme opposite. They simply indicate lens barrel focus rotation, which can be mapped in prime lenses fairly well, but zoom lenses are a real crap shoot, but most likely terrible. A better high priced lens can be less terrible, but accuracy still varies at each zoom, due to both zoom and focus distance (internal focusing, etc). Distance can be extremely inaccurate. See
Nikon TTL BL flash - D-lens distance data accuracy for examples of Nikon lenses. Easy to test yourself. This D-lens distance inaccuracy can really mess up TTL BL direct flash (in Nikon flashes, it is ignored by the way third party flashes don't report head tilt).