题目内容
【题目】脱式计算,能简算的要简算。
3.2×0.25×1.25 2.7×99
3.75×102 8.6×99+8.6
50-1.35-0.65 2.5×4.4
4.5×10.1 2.36×101—2.36
(1.25+0.25)×0.4 98×6.5
25×× ÷÷14
÷×9 63×÷
【答案】1; 267.3;382.5;860;48;11;45.45;236;0.6;637;5;;42;44;
【解析】
3.2×0.25×1.25
=(4×0.8)×0.25×1.25
=(4×0.25)×(0.8×1.25)
=1×1
=1
2.7×99
=2.7×(100-1)
=2.7×100-2.7×1
=270-2.7
=267.3
3.75×102
=3.75×(100+2)
=3.75×100+3.75×2
=375+7.5
=382.5
8.6×99+8.6
=8.6×(99+1)
=8.6×100
=860
50-1.35-0.65
=50-(1.35+0.65)
=50-2
=48
2.5×4.4
=2.5×(4+0.4)
=2.5×4+2.5×0.4
=10+1
=11
4.5×10.1
=4.5×(10+0.1)
=4.5×10+4.5×0.1
=45+0.45
=45.45
2.36×101—2.36
=2.36×(101-1)
=2.36×100
=236
(1.25+0.25)×0.4
=1.5×0.4
=0.6
98×6.5
=(100-2)×6.5
=100×6.5-2×6.5
=650-13
=637
25××
=25×(×)
=25×
=5
÷÷14
=÷(×14)
=÷4
=
÷×9
=×9
=42
63×÷
=28×
=44
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