diff --git a/src/main/java/xyz/zhouxy/plusone/commons/util/Assert.java b/src/main/java/xyz/zhouxy/plusone/commons/util/Assert.java
index 8e06b29..fbfc17d 100644
--- a/src/main/java/xyz/zhouxy/plusone/commons/util/Assert.java
+++ b/src/main/java/xyz/zhouxy/plusone/commons/util/Assert.java
@@ -78,54 +78,45 @@ public class Assert {
     }
 
     // between - int
-    private static boolean between(int value, int min, int max) {
-        return value >= min && value < max;
-    }
 
     public static <E extends Throwable> void between(int value, int min, int max, Supplier<E> e) throws E {
-        Assert.isTrue(between(value, min, max), e);
+        Assert.isTrue(Numbers.between(value, min, max), e);
     }
 
     public static void between(int value, int min, int max, String errorMessage) {
-        Assert.isTrue(between(value, min, max), errorMessage);
+        Assert.isTrue(Numbers.between(value, min, max), errorMessage);
     }
 
     public static void between(int value, int min, int max, String errorMessageTemplate, Object... args) {
-        Assert.isTrue(between(value, min, max), errorMessageTemplate, args);
+        Assert.isTrue(Numbers.between(value, min, max), errorMessageTemplate, args);
     }
 
     // between - long
-    private static boolean between(long value, long min, long max) {
-        return value >= min && value < max;
-    }
 
     public static <E extends Throwable> void between(long value, long min, long max, Supplier<E> e) throws E {
-        Assert.isTrue(between(value, min, max), e);
+        Assert.isTrue(Numbers.between(value, min, max), e);
     }
 
     public static void between(long value, long min, long max, String errorMessage) {
-        Assert.isTrue(between(value, min, max), errorMessage);
+        Assert.isTrue(Numbers.between(value, min, max), errorMessage);
     }
 
     public static void between(long value, long min, long max, String errorMessageTemplate, Object... args) {
-        Assert.isTrue(between(value, min, max), errorMessageTemplate, args);
+        Assert.isTrue(Numbers.between(value, min, max), errorMessageTemplate, args);
     }
 
     // between - double
-    private static boolean between(double value, double min, double max) {
-        return value >= min && value < max;
-    }
 
     public static <E extends Throwable> void between(double value, double min, double max, Supplier<E> e) throws E {
-        Assert.isTrue(between(value, min, max), e);
+        Assert.isTrue(Numbers.between(value, min, max), e);
     }
 
     public static void between(double value, double min, double max, String errorMessage) {
-        Assert.isTrue(between(value, min, max), errorMessage);
+        Assert.isTrue(Numbers.between(value, min, max), errorMessage);
     }
 
     public static void between(double value, double min, double max, String errorMessageTemplate, Object... args) {
-        Assert.isTrue(between(value, min, max), errorMessageTemplate, args);
+        Assert.isTrue(Numbers.between(value, min, max), errorMessageTemplate, args);
     }
 
     // notNull
diff --git a/src/main/java/xyz/zhouxy/plusone/commons/util/NumberUtil.java b/src/main/java/xyz/zhouxy/plusone/commons/util/Numbers.java
similarity index 72%
rename from src/main/java/xyz/zhouxy/plusone/commons/util/NumberUtil.java
rename to src/main/java/xyz/zhouxy/plusone/commons/util/Numbers.java
index 7d8a9a4..365e0fd 100644
--- a/src/main/java/xyz/zhouxy/plusone/commons/util/NumberUtil.java
+++ b/src/main/java/xyz/zhouxy/plusone/commons/util/Numbers.java
@@ -21,12 +21,14 @@ package xyz.zhouxy.plusone.commons.util;
  *
  * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
  */
-public class NumberUtil {
+public class Numbers {
 
-    private NumberUtil() {
+    private Numbers() {
         throw new IllegalStateException("Utility class");
     }
 
+    // sum
+
     public static int sum(final short... numbers) {
         int result = 0;
         for (short number : numbers) {
@@ -66,4 +68,26 @@ public class NumberUtil {
         }
         return result;
     }
+
+    // between
+
+    public static boolean between(short value, short min, short max) {
+        return value >= min && value < max;
+    }
+
+    public static boolean between(int value, int min, int max) {
+        return value >= min && value < max;
+    }
+
+    public static boolean between(long value, long min, long max) {
+        return value >= min && value < max;
+    }
+
+    public static boolean between(float value, float min, float max) {
+        return value >= min && value < max;
+    }
+
+    public static boolean between(double value, double min, double max) {
+        return value >= min && value < max;
+    }
 }