| 用简便方法计算. 0.125×32×25 15.4×1.7+9.3×15.4-15.4 0.8+0.98+0.998+0.9998 4.28×34.5+3.45×57.2. |
| (1)0.125×32×25 =0.125×8×4×25 =0.125×8×(4×25) =1×100 =100; (2)15.4×1.7+9.3×15.4-15.4 =(1.7+9.3-1)×15.4 =10×15.4 =154; (3)0.8+0.98+0.998+0.9998 =1-0.2+1-0.02+1-0.002+1-0.0002 =4-0.2222 =3.7778; (4)4.28×34.5+3.45×57.2 =42.8×3.45+3.45×57.2 =(42.8+57.2)×3.45 =100×3.45 =345. |
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