1999+4568+1234+55等于几
问题描述：
1999+4568+1234+55等于几
答
1999+4568+1234+55
=（1999+1）+（4568+2）+（1234+1）+55-4
=2000+4570+1235+55-4
=2000+4570+（1235+55）-4
=2000+4570+1290-4
=2000+5860-4
=7860-4
=7856