脱式计算，能简算的要简算．12.5×32×2.56.8×9.924.6×4.6+246×0.44+24.66.28÷0.8÷54.85÷0.25+1.25÷0.25．

Question

脱式计算，能简算的要简算．
12.5×32×2.5           
6.8×9.9         
24.6×4.6+246×0.44+24.6
6.28÷0.8÷5            
4.85÷0.25+1.25÷0.25．

Answer 1

（1）12.5×32×2.5  
=12.5×4×8×2.5
=（12.5×4）×（8×2.5）
=50×20
=1000；

（2）6.8×9.9   
=6.8×（10-0.1）
=6.8×10-6.8×0.1
=68-0.68
=67.32；
      
（3）24.6×4.6+246×0.44+24.6
=24.6×4.6+24.6×4.4+24.6×1
=24.6×（4.6+4.4+1）
=24.6×10
=246；

（4）6.28÷0.8÷5 
=6.28÷（0.8×5）
=6.28÷4
=1.57；
          
（5）4.85÷0.25+1.25÷0.25
=（4.85+1.25）÷0.25
=6÷0.25
=24．