(1)4×0.8×2.5×1.25=(4×2.5)×(0.8×1.25)=10×1=10(2)7.7×7+7.7×2+7.7=7.7×(7+2+1)=7.7×10=77(3)1000÷32÷0.25÷1.25=1000÷32÷ 1 4 ÷ 5 4 =1000× 1 32 ×4× 4 5 =100.