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1 # 小公主7P1g
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2 # 使用者4709403028801
十五道簡便脫式運算我來做給大家看,2X3十2x7二2X(3十7)二2X10=20,第二題,1.25x2十1.25X8二1.25X(2十8)=1.25x10二12.
5第三題,4x6十5X6=6x(4十5)=6X9二54,第四題,5X3十5X7=5X(3十7’=5X10,第五題6x9十9x4=9x(6十4)二9x10二9第六題2x8十2x3二2X(8十3)=2X11二22
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3 # 飄零書生與wife
簡便脫式運算:
(1)0.25×4×2
=1×2
=2
(2)1.5×8+1.5×12
=1.5×(8+12)
=1.5×20
=30
(3)0.125+0.125×7
=0.125×(1+7)
=0.125×8
=1
(4)2/7×5+2/7×44
=2/7×(5+44)
=2/7×49
=2×7
=14
(5)1/8×9+1/8×15
=1/8×(9+15)
=1/8×24
=3
(6)1/4×3+1/4×21
=1/4×(3+21)
=1/4×24
=6
(7)25×3+25
=25×(3+1)
=25×4
=100
(8)3×75+3×25
=3×(75+25)
=3×100
=300
(9)4×17+4×8
=4×(17+8)
=4×25
=100
(10)7.5×1.5+7.5×2.5
=7.5×(1.5+2.5)
=7.5×4
=30
(11)0.125×3+0.125×5
=0.125×(3+5)
=0.125×8
=1
(12)3/5×4+3/5×6
=3/5×(4+6)
=3/5×10
=6
(13)5×13+5×7
=5×(13+7)
=5×20
=100
(14)0.25×7×4
=0.25×4×7
=1×7
=7
(15)0.5×1.1+0.5×0.9
=0.5×(1.1+0.9)
=0.5×2
=1
回覆列表
1.45+15×6= 135
2.250÷5×8=400
3.6×5÷2×4=60
4.30×3+8=98
5.400÷4+20×5= 200
6.10+12÷3+20=34
7.(80÷20+80)÷4=21
8.70+(100-10×5)=120
9.360÷40+10= 19
10.40×20-200= 600
11.(80-25)*2= 110
12.70+45=115
13.90×2÷3= 60
14.16×6÷3= 32
15.300×6÷9= 200