①3.7×1.4×0.05
=3.7×(1.4×0.05)
=3.7×0.07
=0.259;
②2.7×3.7+0.37×73
=2.7×3.7+3.7×7.3
=(2.7+7.3)×3.7
=10×3.7
=37;
③8.7×99
=8.7×(100-1)
=8.7×100-8.7×1
=870-8.7
=861.3;
④1.25×0.4×80×2.5
=(1.25×80)×(0.4×2.5)
=100×1
=100;
⑤0.525÷0.25÷2
=0.525÷(0.25×2)
=0.525÷0.5
=1.05.