178×99+78的简便计算

问题描述:

178×99+78的简便计算

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=178×(100-1)+78
=17800-178+78
=17800-100
=17700

178×99+78
=178×(99+1)-178+78
=17800-178+78
=17622+78
=17700

178×99+78
=(100+78)×99+78
=9900+78×99+78
=9900+78×(99+1)
=9900+7800
=17700

178×99+78
=(100+78)×99+78
=100×99+78×99+78
=9900+78×(99+1)
=9900+78×100
=9900+7800
=17700