I am an old cashier and so was my mom. I learned to count change at an early age and use it all the time.
I made sure my children learned (34 and 36) and my son is a trucker and adds mileage and fuel consumption stuff like crazy in his head.
Taught the kids to read a regular clock before I would give them a digital and had a harder time teaching them military time, but both kids use it in their jobs.
Just last week in my one nursing class, teacher asked if anyone knew how to tell military time. Only two of us raised our hands. The others acted as though she was talking a foreign language. She said they need to learn because the job will require it.
All good skills to have.