用简便方法计算.
例如:72÷12
=72÷2÷6
=36÷6
=6
48÷16
45÷3÷3
90÷15
56÷14
54÷18
388﹣199
=388﹣200+1
=188+1
=189
1000﹣99﹣1﹣98﹣2﹣97﹣3﹣96﹣4
434﹣197
999+99+9.
脱式计算,能简算得要简算.
5.46÷3.9+4.5×2.3
4.23×9.9+0.423
2.58﹣(3.5﹣2.4)
78÷0.25÷0.4.
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
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