diff --git a/src/modules/math/README b/src/modules/math/README
index b0b2ae0f155..e9fe6fadcf5 100644
--- a/src/modules/math/README
+++ b/src/modules/math/README
@@ -29,6 +29,7 @@ Daniel-Constantin Mierla
               3.2. math_logN(x, res)
               3.3. math_log2(x, res)
               3.4. math_log10(x, res)
+              3.5. math_sqrt(x, res)
 
    List of Examples
 
@@ -36,6 +37,7 @@ Daniel-Constantin Mierla
    1.2. math_logN usage
    1.3. math_log2 usage
    1.4. math_log10 usage
+   1.5. math_sqrt usage
 
 Chapter 1. Admin Guide
 
@@ -53,6 +55,7 @@ Chapter 1. Admin Guide
         3.2. math_logN(x, res)
         3.3. math_log2(x, res)
         3.4. math_log10(x, res)
+        3.5. math_sqrt(x, res)
 
 1. Overview
 
@@ -83,6 +86,7 @@ Chapter 1. Admin Guide
    3.2. math_logN(x, res)
    3.3. math_log2(x, res)
    3.4. math_log10(x, res)
+   3.5. math_sqrt(x, res)
 
 3.1.  pow(base, power, res)
 
@@ -140,3 +144,17 @@ Chapter 1. Admin Guide
     $var(x) = 100;
     math_log10("$var(x)", "$var(res)");
 ...
+
+3.5.  math_sqrt(x, res)
+
+   The function computes the square root of x and stores the result in
+   res.
+
+   This function can be used from ANY_ROUTE.
+
+   Example 1.5. math_sqrt usage
+...
+    math_sqrt("16", "$var(res)");
+    $var(x) = 16;
+    math_sqrt("$var(x)", "$var(res)");
+...