diff --git a/src/main/java/me/hatter/math/Prime.java b/src/main/java/me/hatter/math/Prime.java
new file mode 100644
index 0000000..58a3eb4
--- /dev/null
+++ b/src/main/java/me/hatter/math/Prime.java
@@ -0,0 +1,18 @@
+package me.hatter.math;
+
+public class Prime {
+
+    // 试除法
+    // https://oi-wiki.org/math/number-theory/prime/
+    public static boolean isPrimeTryingDivision(long a) {
+        if (a < 2) {
+            return false;
+        }
+        for (long i = 2; i < a; i++) {
+            if (a % i == 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+}