diff --git a/app/src/main/java/me/bello/mathscalc/activity/CalcActivity.java b/app/src/main/java/me/bello/mathscalc/activity/CalcActivity.java
index fa56348..f489c59 100755
--- a/app/src/main/java/me/bello/mathscalc/activity/CalcActivity.java
+++ b/app/src/main/java/me/bello/mathscalc/activity/CalcActivity.java
@@ -345,7 +345,11 @@
             list.get(currentPosition).setRight(false);
         }
         //保存答案
-        list.get(currentPosition).setAnswer(answerText.getText().toString().trim());
+        if(TextUtils.isEmpty(answerText.getText().toString().trim())) {
+            list.get(currentPosition).setAnswer("-1");
+        } else {
+            list.get(currentPosition).setAnswer(answerText.getText().toString().trim());
+        }
 
 
         //统计对错