早教吧 育儿知识 作业答案 考试题库 百科 知识分享

81.5*15.8+81.5*51.8+67.6*18.5(速算)53.5*35.3+53.5*43.2+78.5*46.5(速算)

题目详情
81.5*15.8+81.5*51.8+67.6*18.5 (速算) 53.5*35.3+53.5*43.2+78.5*46.5 (速算)
▼优质解答
答案和解析
81.5*15.8+81.5*51.8+67.6*18.5 =81.5×(15.8+51.8)+67.6×18.5 =81.5×67.6+67.6×18.5 =67.6×(81.5+18.5) =67.6×100 =6760 53.5*35.3+53.5*43.2+78.5*46.5 =53.5×(35.3+43.2)+78.5×46.5 =53.5×78.5+78....