用简便方法计算.(用梯等式,43×201 (38+14)×25 99×2138×7+62×7 16×29-16×21 102×45 98×32 44×25 256×7-56×748×101-48 99×62+62 27×37+37×23
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用简便方法计算.(用梯等式,43×201 (38+14)×25 99×2138×7+62×7 16×29-16×21 102×45 98×32 44×25 256×7-56×748×101-48 99×62+62 27×37+37×23
用简便方法计算.(用梯等式,43×201 (38+14)×25 99×21
38×7+62×7 16×29-16×21 102×45 98×32 44×25 256×7-56×7
48×101-48 99×62+62 27×37+37×23
用简便方法计算.(用梯等式,43×201 (38+14)×25 99×2138×7+62×7 16×29-16×21 102×45 98×32 44×25 256×7-56×748×101-48 99×62+62 27×37+37×23
43×201
=43*(200+1)
=43*200+43*1
=8600+43
=8643
(38+14)×25
=52*25
=13*4*25
=13*100
=1300
99×21
=(100-1)*21
=100*21-1*21
=2100-21
=2079
38×7+62×7
=(38+62)*7
=100*7
=700
16×29-16×21
=16*(29-21)
=16*8
=128
102×45
=(100+2)*45
=100*45+2*45
=4500+90
=4590
98×32
=(100-2)*32
=100*32-2*32
=3200-64
=3136
44×25
=11*4*25
=11*100
=1100
256×7-56×7
=(256-56)*7
=200*7
=1400
48×101-48
=48*(101-1)
=48*100
=4800
99×62+62
=(99+1)*62
=100*62
=6200
27×37+37×23
=37*(27+23)
=37*50
=1850