分析:①先算加法,再算除法,再算乘法,最后算減法;
②根據(jù)乘法分配律進(jìn)行計算;
③根據(jù)乘法分配律進(jìn)行計算;
④根據(jù)乘法分配律和乘法結(jié)合律進(jìn)行計算;
⑤根據(jù)乘法交換律和結(jié)合律進(jìn)行計算;
⑥根據(jù)乘法分配律進(jìn)行計算.
解答:解:
①7.2÷8×4-(0.77+0.33),
=7.2÷8×4-1.1,
=0.9×4-1.1,
=3.6-1.1,
=2.5;
②(
+18%)÷9,
=
÷9+18%÷9,
=0.1+0.02,
=0.12;
③(125+75%)×8,
=125×8+0.75×8,
=1000+6,
=1006;
④0.9+99×0.9+1.9×4×0.5,
=0.9×(1+99)+1.9×(4×0.5),
=0.9×100+1.9×2,
=90+3.8,
=93.8;
⑤1.25×32×25%,
=1.25×(4×8)×0.25,
=(1.25×8)×(4×0.25),
=10×1,
=10;
⑥962÷37-222÷37,
=(962-222)÷37,
=740÷37,
=20.
點(diǎn)評:四則運(yùn)算,先弄清運(yùn)算順序,然后再進(jìn)行計算,能簡算的要簡算.