Son las diez y media.
Half past ten is 30 minutes after 10 o'clock. (10:30)
Diez
"Son las diez y media"
Quarter to 10.
The ordinal number for ten in Spanish is "décimo"
one hour and ten minuts
Diez y media means "ten-thirty" in Spanish. It refers to the time of 10:30 on a clock or watch.
10 1/2
10:45
Ten to nine on a clock means it is ten minutes until it is nine o'clock. Half past ten means it is 10:30, or a half an hour past ten. Quarter past nine/quarter to 9 means it is 9:15/8:45, or 15 minutes after/before nine.
Seven past ten