diff --git a/core/src/main/java/it/cavallium/warppi/math/rules/dsl/patterns/NumberPattern.java b/core/src/main/java/it/cavallium/warppi/math/rules/dsl/patterns/NumberPattern.java
new file mode 100644
index 00000000..075a21c1
--- /dev/null
+++ b/core/src/main/java/it/cavallium/warppi/math/rules/dsl/patterns/NumberPattern.java
@@ -0,0 +1,35 @@
+package it.cavallium.warppi.math.rules.dsl.patterns;
+
+import it.cavallium.warppi.math.Function;
+import it.cavallium.warppi.math.functions.Number;
+import it.cavallium.warppi.math.rules.dsl.VisitorPattern;
+
+import java.math.BigDecimal;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * Matches and generates a specific number.
+ */
+public class NumberPattern extends VisitorPattern {
+    private final BigDecimal value;
+
+    public NumberPattern(BigDecimal value) {
+        this.value = value;
+    }
+
+    @Override
+    public Optional<Map<String, Function>> visit(Number number) {
+        if (number.getTerm().compareTo(value) == 0) {
+            return Optional.of(new HashMap<>());
+        } else {
+            return Optional.empty();
+        }
+    }
+
+    @Override
+    public Function replace(Map<String, Function> subFunctions) {
+        return new Number(null, value);
+    }
+}
diff --git a/core/src/test/java/it/cavallium/warppi/math/rules/dsl/PatternTest.java b/core/src/test/java/it/cavallium/warppi/math/rules/dsl/PatternTest.java
index 448154ca..37f188fa 100644
--- a/core/src/test/java/it/cavallium/warppi/math/rules/dsl/PatternTest.java
+++ b/core/src/test/java/it/cavallium/warppi/math/rules/dsl/PatternTest.java
@@ -4,11 +4,12 @@ import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.functions.Number;
 import it.cavallium.warppi.math.functions.Subtraction;
 import it.cavallium.warppi.math.functions.Sum;
-import it.cavallium.warppi.math.functions.Variable;
+import it.cavallium.warppi.math.rules.dsl.patterns.NumberPattern;
 import it.cavallium.warppi.math.rules.dsl.patterns.SubFunctionPattern;
 import it.cavallium.warppi.math.rules.dsl.patterns.SumPattern;
 import org.junit.Test;
 
+import java.math.BigDecimal;
 import java.util.Map;
 import java.util.Optional;
 
@@ -78,4 +79,17 @@ public class PatternTest {
         );
         assertFalse(pattern.match(shouldNotMatch).isPresent());
     }
+
+    @Test
+    public void numberPattern() {
+        final Pattern pattern = new NumberPattern(BigDecimal.valueOf(Math.PI));
+
+        final Function shouldNotMatch = new Number(null, 2);
+        assertFalse(pattern.match(shouldNotMatch).isPresent());
+
+        final Function shouldMatch = new Number(null, Math.PI);
+        final Optional<Map<String, Function>> subFunctions = pattern.match(shouldMatch);
+        assertTrue(subFunctions.isPresent());
+        assertEquals(shouldMatch, pattern.replace(subFunctions.get()));
+    }
 }
\ No newline at end of file