①2.07÷2.5÷0.4, =2.07÷(2.5×0.4), =2.07÷1, =2.07; ②21.36÷0.8-12.9, =26.7-12.9, =13.8; ③0.125×32×2.5, =0.125×8×4×2.5, =(0.125×8)×(4×2.5), =1×10, =10; ④0.65×201, =0.65×(200+1), =0.65×200+0.65×1, =130+0.65, =130.65; ⑤1.2×2.5+8×0.25, =1.2×2.5+0.8×2.5, =(1.2+0.8)×2.5, =2×2.5, =5; ⑥50.4×19+50.4, =50.4×(19+1), =50.4×20, =1008. |