The word “minute” does not always refer to a clock. In an angular coordinate, it is part of the way a degree is divided. Recognising that difference helps you read a position without silently changing its meaning.
Start with sixty
NOAA’s latitude explanation describes sixty minutes in a degree and sixty seconds in a minute. Latitude also needs a north or south label to identify its hemisphere.
For a purely numerical example, 12 degrees 30 minutes north becomes 12.5 degrees north: 30 divided by 60 is 0.5. It does not become 12.30 degrees. In the reverse direction, 0.25 of a degree is 15 minutes.
Keep the format beside the value
Make two columns headed “degrees and minutes” and “decimal degrees”. Convert three invented examples, then convert them back. The return calculation is a useful check for a misplaced decimal.
Do not copy these invented numbers into navigation equipment. Actual coordinate handling also requires the correct coordinate system, datum, hemisphere or sign convention, and the complete position. An arithmetic exercise cannot verify a real location.
When saving a position from a reference, preserve its original notation and context instead of immediately rewriting it. If you are uncertain about a symbol, add it to your glossary with a checked example.