Question

小学六年级奥数简便计算

2.4×20.6+33.1×7.6

Answer 1

33.1*10-12.5*2.4
=301

Answer 2

33.1*10-12.5*2.4
=301

Answer 3

2.4×20.6+33.1×7.6
=2.4×20.6+33.1×(10-2.4)
=2.4×20.6+33.1×10-2.4×33.1
=331-2.4×(33.1-20.6)
=331-2.4×12.5
=331-30
=301
这样可以吗？？？？？？？？

Answer 4

2.4*20.6+20.6*7.6+12.5*7.6
=206+25*0.5*4*1.9
=206+25*4*0.95
=206+100*0.95
=206+95
=301

Answer 5

2.4×20.6+33.1×7.6
=2.4×20.6+（20.6+12.5）×7.6
=2.4×20.6+20.6×7.6+12.5×7.6
=20.6×（2.4+7.6）+12.5×7.6
=13×10+7.6×10+12.5×7.6
=13×10+7.6×22.5
=130+3.8×45
=130+19×9
=130+171
=301
希望能帮助你，O(∩_∩)O谢谢！