3,75km+2,5hm+400cm= m

3,75km = 3750 m
2,5hm = 250 m
400 cm = 4 m
4004 m
mungkin

3,75 km = 3,75 × 1000 = 3750 m
2,5 hm   = 2,5 × 100     = 250 m
400 cm  = 400 ÷ 100    =  4 m

3750 m + 250 m + 4 m = 4004 m