请运用简便方法计算.
(1)5.7×1.4+1.4×4.3 (2)9.05﹣3.86﹣3.14 (3)6.84×10.1
(4)87×2.5+8.7×75 (5)1+2+3+4+5+6+…+97+98+99 (6)0.7777×0.7+0.1111×5.1.
用简便方法计算下面各题
1.Ol×6.3 2.18×3.12+6.88×2.18 4.4×25
0.25×39+0.25 0.8×5.67×12.5 4.4×3.8+6.6×3.8﹣3.8
8.6×102 (0.2+4)×25 12.5×32×0.25.
3.51×49+35.1×5.1+49×51
66666×6+88888×8
2772÷28+34965÷35
2006×2007×20082008﹣2006×2008×20072007.
运用定律计算下面各题.
24×125
36×(10+15)
45×125﹣25×45
105×101﹣105
99×365
198×99+2×99.
能用简便的要用简便算
399×99+399 283﹣(125+83) 1+2+3+4…+99+100 137×13+137×6+137 2007+2008+2009+6.
计算:
①3×(x+9)=27
②16×8﹣7x=23
③7.5﹣7.5×0.5﹣2.6×0.8
④13.7×6.5+5.9×13.7﹣12.4×3.7
⑤50×[(0.2+4.8﹣4.8+0.2)÷2]
⑥11.25+21.25+31.25+41.25+51.25+61.25+71.25+81.25.
试题篮
()