diff --git a/example/ex6/CMakeLists.txt b/example/ex6/CMakeLists.txt
index 2b933f7d..ce583825 100644
--- a/example/ex6/CMakeLists.txt
+++ b/example/ex6/CMakeLists.txt
@@ -10,6 +10,6 @@ xo_include_options2(${SELF_EXE})
 # dependencies..
 
 xo_self_headeronly_dependency(${SELF_EXE} xo_unit)
-#xo_dependency(${SELF_EXE} reflect)
+xo_dependency(${SELF_EXE} xo_flatstring)
 
 # end CMakeLists.txt
diff --git a/example/ex6/ex6.cpp b/example/ex6/ex6.cpp
index a3e7b723..3775cf3d 100644
--- a/example/ex6/ex6.cpp
+++ b/example/ex6/ex6.cpp
@@ -1,19 +1,39 @@
 /** @file ex6.cpp **/
 
-#include "xo/unit/mpl/quantity.hpp"
+#include "xo/unit/quantity.hpp"
+#include "xo/unit/quantity_iostream.hpp"
+#include "xo/flatstring/int128_iostream.hpp"
 #include <iostream>
 
 int
 main () {
-    namespace u = xo::unit::units;
-    namespace qty = xo::unit::qty;
-    using namespace std;
+    using xo::qty::quantity;
+    namespace q = xo::qty::qty;
+    using xo::flatstring;
 
-    auto t1 = qty::milliseconds(25.0);
-    auto t1_usec = t1.with_unit<u::microsecond>();
-    auto t1_sec = t1.with_unit<u::second>();
+    /* 20% volatility over 360 days */
+    auto q1 = q::volatility_360d(0.2);
+    /* 10% volatility over 30 days */
+    auto q2 = q::volatility_30d(0.1);
 
-    cerr << "t1: " << t1 << ", t1_usec: " << t1_usec << ", t1_sec: " << t1_sec << endl;
+    //quantity<nu::volatility_360d> q2p = q2;
+
+    /* 10% volatility per 30 days
+     *  ~ (10% * sqrt(360/30)) volatility over 360 days
+     *  ~ (10% * 3.4641)
+     *  ~ 0.34641yr360^(-1/2)
+     */
+
+    auto sum = q1 + q2;
+    auto prod = q1 * q2;
+
+    static_assert(sum.abbrev() == flatstring("yr360^(-1/2)"));
+    static_assert(prod.abbrev() == flatstring("yr360^-1"));
+
+    std::cerr << "q1: " << q1 << std::endl;
+    std::cerr << "q2: " << q2 << std::endl;
+    std::cerr << "q1+q2: " << sum << std::endl;
+    std::cerr << "q1*q2: " << prod << std::endl;
 }
 
 /** end ex6.cpp */