(1)9t-4800kg=4200kg, (2)6t+3500kg=9500kg,
(3)6800kg+3200kg=10t, (4)25t+35t=60t,
(5)9000mL+6000mL=15L, (6)9L-832mL=8168mL,
(7)120L-120mL=0mL, (8)6000mL-3L=3000mL. 故答案为:4200,9500,10,60,15,8168,0,3000.
(1)9t-4800kg=4200kg, (2)6t+3500kg=9500kg,
(3)6800kg+3200kg=10t, (4)25t+35t=60t,
(5)9000mL+6000mL=15L, (6)9L-832mL=8168mL,
(7)120L-120mL=0mL, (8)6000mL-3L=3000mL. 故答案为:4200,9500,10,60,15,8168,0,3000.