Question

3．計(jì)算下列各題，能簡(jiǎn)算的要簡(jiǎn)算

（0.25-$\frac{5}{12}$×$\frac{4}{15}$）÷$\frac{5}{6}$	$\frac{1}{6}$×31+89÷6	0.125×75+$\frac{1}{8}$×23+12.5%×2
2015×$\frac{2013}{2014}$	$\frac{4}{5}$÷[（ $\frac{3}{4}$-$\frac{1}{6}$）×$\frac{4}{7}$]	1.25×0.25×32．

Answer 1

分析 ①先算乘法再算減法，最后算除法．
②用乘法分配律計(jì)算．
③用乘法分配律計(jì)算．
④把2015變成2014+1，用乘法分配律計(jì)算．，
⑤先算減法再算乘法，最后算除法．
⑥把32變成8×4，1.25和8結(jié)合，0.25和結(jié)合，再把兩個(gè)積相乘．

解答 解：①（0.25-$\frac{5}{12}$×$\frac{4}{15}$）÷$\frac{5}{6}$
=（0.25-$\frac{1}{9}$）÷$\frac{5}{6}$
=$\frac{5}{36}×\frac{6}{5}$
=$\frac{1}{6}$

②$\frac{1}{6}$×31+89÷6
=$\frac{1}{6}$×31+89×$\frac{1}{6}$
=$（31+89）×\frac{1}{6}$
=$120×\frac{1}{6}$
=20

③0.125×75+$\frac{1}{8}$×23+12.5%×2
=0.125×（75+23+2）
=0.125×100
=12.5

④2015×$\frac{2013}{2014}$
=（2014+1）×$\frac{2013}{2014}$
=$2014×\frac{2013}{2014}+\frac{2013}{2014}×1$
=2014+$\frac{2013}{2014}$
=$2014\frac{2013}{2014}$


⑤$\frac{4}{5}$÷[（ $\frac{3}{4}$-$\frac{1}{6}$）×$\frac{4}{7}$]
=$\frac{4}{5}$÷[$\frac{7}{12}$×$\frac{4}{7}$]
=$\frac{4}{5}×3$
=$\frac{12}{5}$

⑥1.25×0.25×32
=（1.25×8）×（0.25×4）
=10×1
=10

點(diǎn)評(píng) 考查了用簡(jiǎn)便計(jì)算方法進(jìn)行計(jì)算的能力．