32 2′ 14″- 15 43′32″=3 1 6 1′74″- 15 43′32″= 16 18′42″
56 53′-28 57′=55 1 13′-28 57′=(55-28) ( 1 13-57)′=27 56′
180-46 37 minutes and 45 seconds =179 59' 60 "-46 37' 45" =133 22'15 "
175 16 minutes and 30 seconds+48 minutes divided by 6 =17516' 30 "+8 5' =183 21'30".
125? 12′+36 48′= 16 1? 60′= 162?
22? 30′×8= 176? 240′= 180?
2*(43 16′- 18.5 )=2×﹙43 16′- 18 30′﹚=2×﹙24 46′﹚=48 92′=49 32′
176 52′÷6=29 28′40″
180 -53 19′36〃÷3-25 36′×4
= 180 - 17 46′32″- 100 1 14′
= 179 59′60″- 17 46′32″- 10 1 54″
= 179 59′60″- 1 18 1 10′32″
= 179 59′60″- 1 19 50′32″
=60 9′28″