问题
解答题
|
答案
①1375+450÷18,
=1375+450÷(9×2),
=1375+450÷9÷2,
=1375+50÷2,
=1375+25,
=1400;
②101×43,
=(100+1)×43,
=100×43+1×43,
=4300+43,
=4343;
③
÷7 9
÷2 3
,2 3
=
÷(7 9
×2 3
),2 3
=
×7 9
,9 4
=
;7 4
④20.9+10.2÷(5.2-3.5),
=20.9+10.2÷1.7,
=20.9+6,
=26.9;
⑤
×0.75+0.75×4 5
,1 5
=(
+4 5
)×0.75,1 5
=1×0.75,
=0.75.