4km+7hm+5dam+3km+9hm+8dam=

di jadikan m

=>> 4 km + 7 hm + 5 dam + 3 km + 9 hm + 8 dam

=>> 4.000 m + 700 m + 50 m + 3.000 m + 900 m + 80 m

=>> 8.730 m

4km + 7hm=  110  km-hm10
110hm + 5 dam =1150  hm-dam10
1150dam + 3km = 1153 dam-km
1153km + 9hm = 11620 
11620 + 8 = 11628
maaf kalo salah :)