(2)66 degrees 18 minutes 48 seconds -3 1 degree 40 minutes 23 seconds. =34 degrees, 38 minutes and 25 seconds.

(3) 1 1 degree 25 minutes 26 seconds ×9= 102 degrees 48 minutes 54 seconds.

(4)82 degrees 17 minutes 44 seconds ÷4=4 degrees 34 minutes 26 seconds

(5) As shown in the figure, it is known that O is a point on the straight line AB, OD bisects ∠BOC, ∠COD=67 degrees and 38 minutes, and the degree of ∠AOC is found.

(Graph of Question (5))

180 -67 38′×2= 180 - 135 16′=44 44′

(6) Xiaoming went to the vegetable market to buy tomatoes. He found that when 10 kg of vegetables were put on the scale, the pointer on the indicator turned 180 degrees, and Xiao Ming bought 2.4 kg of tomatoes. The pointer turned _ 43 12' _ _. (expressed in degrees, minutes and seconds)

(7) Draw two rays OB and OC from the endpoint O of the ray OA. If ∠AOB=∠75 degrees 12 minutes ∠BOC=26 degrees 32 minutes, find the degree of ∠AOC.

75 12′+26 32′= 10 1 44′

or

75 12′-26 32′=48 40′