用简便方法计算的小学几道算术题

问题描述:

用简便方法计算的小学几道算术题
41x102
1/5÷6/25-2/7x7/32
1042-384÷16x13
8.8-6.75+9.2-0.25
0.8x3.6-0.8x0.6
(7/12+3/8-23/24)x24
4.86x[1÷(2.1-2.09)]
呃,脱式的…用简便方法解,谢

41x102=(40+1)(100+2)=4000+182=4182
1/5÷6/25-2/7x7/32=1/5*25/6-1/16=5/6-1/16=40/48-3/48=37/481042-384÷1042-1042-384÷16x13=1042-24*13=1042-312=730
8.8-6.75+9.2-0.25=8.8+9.2-0.25-6.75=18-7=11
0.8x3.6-0.8x0.6=0.8×(3.6-0.6)=2.4
(7/12+3/8-23/24)x24=7/12×24+3/8×24-23/24x24=14+9-23=0
4.86x[1÷(2.1-2.09)]=4.86×(1÷0.01)=4.86÷0.01=486