下面各题怎样简便就怎样算.①4×0.8×2.5×12.5②213÷[1-(12+13)]③(2.8+3.85÷3.5)×4.6④(2429+1617)×18+1517.-数学
题文
下面各题怎样简便就怎样算. ①4×0.8×2.5×12.5 ②
③(2.8+3.85÷3.5)×4.6 ④(
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答案
①4×0.8×2.5×12.5; =(4×2.5)×(0.8×12.5); =10×10; =100; ②
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③(2.8+3.85÷3.5)×4.6; =(2.8+1.1)×4.6; =3.9×4.6; =17.94; ④(
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