2)70 42'45"+82 37'25"= 153 20' 10"

3) 120 -36 18'52"=83 4 1'8"

4)82.7 = 82 42'

5)20 18'= 20.3

6)57 30'-27.5 =30

7)48 19'+67 2 1'= 1 15 40'

8)27 40'+ 15.3 = 42 58'

9) 100 15'-79 26'= 20 49'

10)80 24'/3=26 48'

( 1 1) 180 -46′42〃= 179 60′-46′42〃= 179 59′60〃-46′42〃= 179 13′ 18〃

( 12)28 36′+72 06′= 100 42′

( 13)50 24′×3= 150 72′= 15 1 12′

( 14)49 28′52〃÷4= 12.25 07′ 13〃= 12 (0.25×60+07)′ 13〃= 12 22′ 13〃

(15) 17 degrees 25 minutes 18 seconds * 3 = 5 1 degree +75 minutes +54 seconds = 52 degrees 15 minutes 54 seconds (60 minutes becomes 1.

90 -52 degrees 15 minutes and 54 seconds = 89 degrees +59 minutes +60 seconds -52 degrees-15 minutes -54 seconds = 37 degrees +44 minutes +6 seconds = 37 degrees 44 minutes and 6 seconds.

(16)40 degrees 27 minutes /3 = 13 degrees +( 1 degree +27 minutes) /3 = 13 degrees +87 minutes /3 = 13 degrees 29 minutes.

( 17) 180 - 46′42〃= 179 60′- 46′42〃= 179 59′60〃-46′42〃= 179 13′ 18〃

( 18)28 36′+7 2 06′= 100 42′

( 19)50 24′×3= 150 72′= 15 1 12′

(20)49 28′52〃÷4

= 12.25 07′ 13〃

= 12 (0.25×60+07)′ 13〃

= 12 22′ 13〃