diff --git a/numerical/factorial_test.go b/numerical/factorial_test.go
new file mode 100644
index 0000000..1c3c364
--- /dev/null
+++ b/numerical/factorial_test.go
@@ -0,0 +1,23 @@
+package numerical
+
+import "testing"
+
+// Testfactorial tests factorial function
+func Testfactorial(t *testing.T) {
+
+	if factorial(2) != 2 {
+		t.Error("[Error] factorial(2) is wrong")
+	}
+
+	if factorial(3) != 6 {
+		t.Error("[Error] factorial(3) is wrong")
+	}
+
+	if factorial(0) != 1 {
+		t.Error("[Error] factorial(0) is wrong")
+	}
+
+	if factorial(5) != 120 {
+		t.Error("[Error] factorial(5) is wrong")
+	}
+}
diff --git a/numerical/fast_pow_test.go b/numerical/fast_pow_test.go
new file mode 100644
index 0000000..1def84b
--- /dev/null
+++ b/numerical/fast_pow_test.go
@@ -0,0 +1,23 @@
+package numerical
+
+import "testing"
+
+// TestFastPow tests fastpow function
+func TestFastPow(t *testing.T) {
+
+	if FastPow(2, 10) != 1024 {
+		t.Error("[Error] FastPow(2, 10) is wrong")
+	}
+
+	if FastPow(1, 10) != 1 {
+		t.Error("[Error] FastPow(1, 10) is wrong")
+	}
+
+	if FastPow(0, 15) != 0 {
+		t.Error("[Error] FastPow(0, 15) is wrong")
+	}
+
+	if FastPow(10, 2) != 100 {
+		t.Error("[Error] FastPow(0, 15) is wrong")
+	}
+}