题目内容
脱式计算,能简算的用简算. 5.5×17.3+6.7×5.5 |
1.5×105 | 9.07-22.78÷3.4 |
3.8+4.29+2.1+4.2 | 2.65×1.7+1.35×1.7 | 23.4÷7.8-2.1 |
0.75×18÷0.15 | 2.5×3.2×1.25 | 0.26×2.5+0.74×2.5+2.5 |
18.09-7.5×(0.14+1.06) | 9÷[(38.02+1.98)×0.5 | 26×20.2-8.4-1.8 |
90-78.09+4.23 | 32.34÷2.l×0.45 | 15.32-1.8×5-3.46 |
(9-2.78)×15÷3.11 | (1.36+4.85)÷(0.15×6) | 3.6÷〔(1.3+0.6)×5〕 |
0.01+1.01×99 | 89.3×43+38×89.3+893×1.9 | 10.01×101-10.01 |
38×7.3+27×3.8 | 32×1.25×0.25 | 38.75-(24.5+8.75) |
分析:(1)、(2)、(5)、(9)、(19)、(20)、(21)、(22)根据乘法分配律进行简算;
(3)、(6)先算除法,再算减法;
(4)根据加法交换律和结合律进行简算;
(7)、(13)、(14)按照从左向右的顺序进行计算;
(8)、(23)根据乘法交换律和结合律进行简算;
(10)先算加法,再算乘法,最后算减法;
(11)、(18)先算加法,再算乘法,最后算除法;
(12)、(15)先算乘法,再按照从左向右的顺序进行计算;
(16)先算减法,再按照从左向右的顺序进行计算;
(17)先算加法和乘法,再算除法;
(24)根据减法的性质进行简算.
(3)、(6)先算除法,再算减法;
(4)根据加法交换律和结合律进行简算;
(7)、(13)、(14)按照从左向右的顺序进行计算;
(8)、(23)根据乘法交换律和结合律进行简算;
(10)先算加法,再算乘法,最后算减法;
(11)、(18)先算加法,再算乘法,最后算除法;
(12)、(15)先算乘法,再按照从左向右的顺序进行计算;
(16)先算减法,再按照从左向右的顺序进行计算;
(17)先算加法和乘法,再算除法;
(24)根据减法的性质进行简算.
解答:解:(1)5.5×17.3+6.7×5.5
=5.5×(17.3+6.7)
=5.5×24
=132;
(2)1.5×105
=1.5×(100+5)
=1.5×100+1.5×5
=150+7.5
=157.5;
(3)9.07-22.78÷3.4
=9.07-6.7
=2.37;
(4)3.8+4.29+2.1+4.2
=(3.8+4.2)+(4.29+2.1)
=8+6.39
=14.39;
(5)2.65×1.7+1.35×1.7
=(2.65+1.35)×1.7
=4×1.7
=6.8;
(6)23.4÷7.8-2.1
=3-2.1
=0.9;
(7)0.75×18÷0.15
=13.5÷0.15
=90;
(8)2.5×3.2×1.25
=2.5×(4×0.8)×1.25
=(2.5×4)×(0.8×1.25)
=10×1
=10;
(9)0.26×2.5+0.74×2.5+2.5
=(0.26+0.74+1)×2.5
=2×2.5
=5;
(10)18.09-7.5×(0.14+1.06)
=18.09-7.5×1.2
=18.09-9
=9.09;
(11)9÷[(38.02+1.98)×0.5]
=9÷[40×0.5]
=9÷20
=0.45;
(12)26×20.2-8.4-1.8
=525.2-8.4-1.8
=516.8-1.8
=515;
(13)90-78.09+4.23
=11.91+4.23
=16.14;
(14)32.34÷2.l×0.45
=15.4×0.45
=6.93;
(15)15.32-1.8×5-3.46
=15.32-9-3.46
=6.32-3.46
=2.86;
(16)(9-2.78)×15÷3.11
=6.22×15÷3.11
=93.3÷3.11
=30;
(17)(1.36+4.85)÷(0.15×6)
=6.21÷0.9
=6.9;
(18)3.6÷[(1.3+0.6)×5]
=3.6÷[1.9×5]
=3.6÷9.5
=
;
(19)0.01+1.01×99
=0.01+(1+0.01)×99
=0.01+1×99+0.01×99
=0.01×(1+99)+99
=0.01×100+99
=1+99
=100;
(20)89.3×43+38×89.3+893×1.9
=89.3×43+38×89.3+89.3×19
=89.3×(43+38+19)
=89.3×100
=8930;
(21)10.01×101-10.01
=10.01×(101-1)
=10.01×100
=1001;
(22)38×7.3+27×3.8
=3.8×73+27×3.8
=3.8×(73+27)
=3.8×100
=380;
(23)32×1.25×0.25
=(4×8)×1.25×0.25
=(4×0.25)×(8×1.25)
=1×10
=10;
(24)38.75-(24.5+8.75)
=38.75-24.5-8.75
=38.75-8.75-24.5
=30-24.5
=5.5.
=5.5×(17.3+6.7)
=5.5×24
=132;
(2)1.5×105
=1.5×(100+5)
=1.5×100+1.5×5
=150+7.5
=157.5;
(3)9.07-22.78÷3.4
=9.07-6.7
=2.37;
(4)3.8+4.29+2.1+4.2
=(3.8+4.2)+(4.29+2.1)
=8+6.39
=14.39;
(5)2.65×1.7+1.35×1.7
=(2.65+1.35)×1.7
=4×1.7
=6.8;
(6)23.4÷7.8-2.1
=3-2.1
=0.9;
(7)0.75×18÷0.15
=13.5÷0.15
=90;
(8)2.5×3.2×1.25
=2.5×(4×0.8)×1.25
=(2.5×4)×(0.8×1.25)
=10×1
=10;
(9)0.26×2.5+0.74×2.5+2.5
=(0.26+0.74+1)×2.5
=2×2.5
=5;
(10)18.09-7.5×(0.14+1.06)
=18.09-7.5×1.2
=18.09-9
=9.09;
(11)9÷[(38.02+1.98)×0.5]
=9÷[40×0.5]
=9÷20
=0.45;
(12)26×20.2-8.4-1.8
=525.2-8.4-1.8
=516.8-1.8
=515;
(13)90-78.09+4.23
=11.91+4.23
=16.14;
(14)32.34÷2.l×0.45
=15.4×0.45
=6.93;
(15)15.32-1.8×5-3.46
=15.32-9-3.46
=6.32-3.46
=2.86;
(16)(9-2.78)×15÷3.11
=6.22×15÷3.11
=93.3÷3.11
=30;
(17)(1.36+4.85)÷(0.15×6)
=6.21÷0.9
=6.9;
(18)3.6÷[(1.3+0.6)×5]
=3.6÷[1.9×5]
=3.6÷9.5
=
36 |
95 |
(19)0.01+1.01×99
=0.01+(1+0.01)×99
=0.01+1×99+0.01×99
=0.01×(1+99)+99
=0.01×100+99
=1+99
=100;
(20)89.3×43+38×89.3+893×1.9
=89.3×43+38×89.3+89.3×19
=89.3×(43+38+19)
=89.3×100
=8930;
(21)10.01×101-10.01
=10.01×(101-1)
=10.01×100
=1001;
(22)38×7.3+27×3.8
=3.8×73+27×3.8
=3.8×(73+27)
=3.8×100
=380;
(23)32×1.25×0.25
=(4×8)×1.25×0.25
=(4×0.25)×(8×1.25)
=1×10
=10;
(24)38.75-(24.5+8.75)
=38.75-24.5-8.75
=38.75-8.75-24.5
=30-24.5
=5.5.
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
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