Question

急！速算巧算六年级奥数题！！

98989898×99999999÷10101010÷11111111
12.9÷0.72＋43.5÷3.6
472634×472634＋472635×472635－472633×472635－472634×472636
47.85÷6.38×0.638
36.363÷（1.2121×4)
123＋234＋345＋456＋567＋678

Answer 1

你好：

98989898×99999999÷10101010÷11111111
=(98989898÷10101010)×(99999999÷11111111)
=9.8×9
=88.2

12.9÷0.72＋43.5÷3.6
=64.5÷3.6+43.5÷3.6
=(64.5+43.5)÷3.6
=108÷3.6
=30

472634×472634＋472635×472635－472633×472635－472634×472636
=(472634×472634-472633×472635)+(472635×472635-472634×472636)
=1+1
=2

47.85÷6.38×0.638
=47.85×(0.638÷6.38)
=47.85×(1/10)
=4.785

36.363÷(1.2121×4)
=(36.363÷1.2121)÷4
=30÷4=7.5

123＋234＋345＋456＋567＋678
=(3+4+5+6+7+8)×1+(2+3+4+5+6+7)×10+(1+2+3+4+5+6)×100
=33+270+2100
=2403