早教吧 育儿知识 作业答案 考试题库 百科 知识分享

3.6×31.4+43.9×6.4等于多少,用简便计算

题目详情
3.6×31.4+43.9×6.4等于多少,用简便计算
▼优质解答
答案和解析
43.9可以化成(31.4+12.5),然后式子变成
3.6x31.4+(31.4+12.5)x6.4
=3.6x31.4+31.4x6.4+12.5x6.4
=10x31.4+12.5x(8x8x0.1)
=314+80
=394