Question

请教奥数题

用简便方法计算

Answer 1

3.原式=7.6×1.75+1.75×2.4
=（7.6+2.4）×1.75
=10×1.75
=17.5
4.原式=666652.5×88+88×333347.2
=（666652.5+333347.5）×88
=1000000×88
=88000000
5.原式=1.2×33.3+1.2×66.7
=1.2×（33.3+66.7）
=1.2×100
=120
6.原式=（7.2+2.8）×14.5+2.5×2.8
=10×14.5+2.5×4×0.7
=145+7
=152
7.原式=254×（256/255+1/255）
=254×257/255
=（255-1）×257/255
=257-1/255
=256又254/255
8.原式=12.8×（34.5+12.3）+46.8×87.2
=12.8×46.8+46.8×87.2
=（12.8+87.2）×46.8
=100×46.8
=4680

Answer 2

一起动动脑