简便计算： 53x54+54x16+69x25+2 - 知识问答

简便计算： 53x54+54x16+69x25+21x69 [98+95+100+99+100+96+96+97+99]

2个回答

53×54+54×16+69×25+21×69
=54×(53+16)+69×(25+21)
=54×69+69×46
=69×(54+46)
=69×100
=6900
(98+95+100+99+100+96+96+97+99)÷8
=(100-2+100-5+100+100-1+100+100-4+100-4+100-3+100-1)÷8
=(900-2-5-1-4-4-3-1)÷8
=(900-20)÷8
=880÷8
=110

相关问题