Răspuns:
Explicație pas cu pas:
5.a. 5m+70dm=5m+7m=12m
19hm+140km=19hm+14hm=33hm
5.600cm+84m=56m+84m=140m
310dam+9hm=31hm+9hm=40hm
.b. 6km+4.500dam=6km+45km=51km
67dam+2.800cm=67.000cm+2.800cm=69.800cm
19.000mm+15hm=19.000mm+1.500.000mm=1.519.000mm
270mm+16m=270mm+16.000mm=16.270mm