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″