Question

求下列题目的巧算（急~~~~~~）

1. 156×157.157-157×156.156
2. （8.88+8.88+8.88+8.88）×1.25
3. （6.4×7.5×8.1）÷（3.2×2.5×2.7）
4. 20.86÷12.5+0.8÷12.5-9.16÷12.5

Answer 1

1. 156×157.157-157×156.156
=156 ×157×1.001-157×156×1.001
=0

2.（8.88+8.88+8.88+8.88）×1.25
=(1.11+1.11+1.11+1.11)×8×1.25
=4.44×10
=44.4

3. （6.4×7.5×8.1）÷（3.2×2.5×2.7）
= (6.4÷3.2)×(7.5÷2.5)×(8.1÷2.7)
=2×3×3
=18

4. 20.86÷12.5+0.8÷12.5-9.16÷12.5
=(20.86+0.8-9.16)÷12.5
=12.5÷12.5
=1