43×47+57×37+57能简便远算吗?如果能,应该怎样简便计算?
问题描述:
43×47+57×37+57能简便远算吗?如果能,应该怎样简便计算?
答
43×47+57×37+57
=(100-57)×47+57×37+57
=100x47-57x47+57×37+57
=4700-57×(47-37)+57
=4700-570+57
=4187
或者
43×47+57×37+57
=43×(57-10)+57×37+57
=43×57-43x10+57×37+57
=43×57+57×37+57-43x10
=57x(43+37)+57-43x10
=57x80-43x10+57
=4560-430+57
=4130+57
=4187