(1)13.7-(5.4+3.7) =13.7-3.7-5.4 =10-5.4 =4.6 (2)1.25×3.2×2.5 =1.25×4×0.8×2.5 =(1.25×0.8)×(4×2.5) =1×10 =10 (3)8×(12.5+1.25) =8×12.5+8×1.25 =100+10 =110