5.46-1.79+6.54-8.21 简便计算4.71-(1.6+17.1)简便计算0.25×12.5×320 简便计算我只是想确认一下.

5.46-1.79+6.54-8.21
=（5.46+6.54）-（1.79+8.21）
=12-10
=2
4.71-(1.6+17.1)
=4.71-18.71+0.01
=-14+0.01
=-13.99
0.25×12.5×320
=0.25*4*12.5*80
=1000