用简便方法计算 ．
25×2×4×1599×99+99146+158﹣46+42 （20+4）×25．
35×（7×3）=35×7+35×3． ．
计算下面各题，能简算的要写出简算过程．
①6.72+2.08×4×1.5
②12.56÷2.5÷0.4
③2.85×4.7+28.5×0.53
④9.88÷[5×（7.34﹣6.96）]
⑤2.5×3.2×1.25
⑥0.56×99．
计算下面各题，怎样简便怎样算．
0.85×2010.5×4.85×82.5×48﹣48
2.7+4.29+2.71+6.31.2×3.5+8.8×3.5．
能用简算的用简便算法计算，写出简算过程．
5.4×2.08﹣5.4×1.087.68×0.25×4 8.2×2.5+17.5（12.4+16.8）÷0.4．
