其它
If Anna takes one step forward, it means she walks $"+1"$ step; If Anna takes one step backward, it means she walks $"-1"$ step. Now, Anna walks $"-5"$ steps, then she walks $"+4"$ steps, then she walks another $"-1"$ step. Anna\textquotesingle s position is from her original location. 
Overseas Competition->Knowledge Point->Calculation Modules->Negative Numbers
Since walking one step forward and one step backward gets you back to your original location. Anna takes $4$ steps foward and $1+5=6$ steps backward.  $6-4=2$(steps)  Therefore, Anna is now $2$ steps backward from her original location. 