用简便方法计算102x28
用简便方法计算102x28
102×28
=(100+2)×28
=100×28+2×28
=2800+56
=2856
用简便方法计算102x21
102x21
=(100+2)x21
=(100x21)+(2x21)
=2100+42
=2142
用简便方法计算102x24-48
102x24-48
=102x24-2x24
=(102-2)x24
=100x24=2400
或102x24-48
=(100+2)x24-48
=100x24+2x24-48
=2400+48-48
=2400
希望能帮到你!
用简便方法计算42x28+56x28+28x2
用简便方法计算
42x28+56x28+28x2
=28×(42+56+2)
=28×100
=2800
用简便方法计算102x20一2x20
102x20-2x20
=20x(102-2)
=20x100
=2000
72x26+26x28用简便方法计算
72x26+26x28
=(72+28)x26
=100x26
=2600
72x26+36x28用简便方法计算
原式=72×26+(26+10)×28
=72×26+26×28+10×28
=(72+28)×26+280
=100×26+280
=2600+280
=2880
12x102x24的简便方法计算
简便方法计算
12x102x24
=(12×24)x102
=288×(100+2)
=288×100+288×2
=28800+576
=29376