小学四年级巧算(脱式计算)1.66×21+19×21+85×192.36×111+888×8

问题描述:

小学四年级巧算(脱式计算)
1.66×21+19×21+85×19
2.36×111+888×8

(1)66x21+19x21+85x19
=(66+19)x21+85x19
=85x21+85x19
=85x(21+19)
=85x40
=3400
(2)36x111+888x8
=36x111+111x8x8
=36x111+111x64
=(36+64)x111
=100x111
=11100