diff --git a/02-primitives/01-numbers/.README.md b/02-primitives/01-numbers/.README.md
new file mode 100644
index 0000000..4ad7829
--- /dev/null
+++ b/02-primitives/01-numbers/.README.md
@@ -0,0 +1,7 @@
+# Numbers - Calculate the area of shapes
+
+Write a small function with multiple input parameters and return the area of {{index . "shape"}}. The formula: {{index . "formula"}}.
+
+Please be aware that you have to specify input parameters based on the given formula. Every parameter should be float64 and you have to return a float64 number.
+
+In the file `exercise.go` near the placeholder `// INSERT YOUR CODE HERE`.
\ No newline at end of file
diff --git a/02-primitives/01-numbers/.exercise_test.go b/02-primitives/01-numbers/.exercise_test.go
new file mode 100644
index 0000000..b02505b
--- /dev/null
+++ b/02-primitives/01-numbers/.exercise_test.go
@@ -0,0 +1,30 @@
+package numbers
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const r float64 = 3.4
+const a float64 = 3.6
+const b float64 = 4.2
+const h float64 = 6.9
+
+
+func TestArea(t *testing.T) {
+	switch "{{index . "shape"}}"{
+	case "Circle":
+		assert.Equal(t, area(r, a, b, h), 36.32)
+	case "Ellipse":
+		assert.Equal(t, area(r, a, b, h), 47.5)
+	case "Trapezoid":
+		assert.Equal(t, area(r, a, b, h), 26.91)
+	case "Pentagon":
+		assert.Equal(t, area(r, a, b, h), 22.297)
+	case "Hexagon":
+		assert.Equal(t, area(r, a, b, h), 33.67)
+	case "Octagon":
+		assert.Equal(t, area(r, a, b, h), 62.58)
+	}
+}
diff --git a/02-primitives/01-numbers/README.md b/02-primitives/01-numbers/README.md
new file mode 100644
index 0000000..90c149f
--- /dev/null
+++ b/02-primitives/01-numbers/README.md
@@ -0,0 +1 @@
+# PLEASE RUN make generate
diff --git a/02-primitives/01-numbers/exercise.go b/02-primitives/01-numbers/exercise.go
new file mode 100644
index 0000000..c29821c
--- /dev/null
+++ b/02-primitives/01-numbers/exercise.go
@@ -0,0 +1,8 @@
+package numbers
+
+//go:generate go run ../../exercises-cli.go -student-id=$STUDENT_ID generate
+
+// area will give back the area of the given shape.
+func area(r, a, b, h float64) float64 {
+	// INSERT YOUR CODE HERE
+}
diff --git a/02-primitives/01-numbers/exercise.yaml b/02-primitives/01-numbers/exercise.yaml
new file mode 100644
index 0000000..a62b274
--- /dev/null
+++ b/02-primitives/01-numbers/exercise.yaml
@@ -0,0 +1,14 @@
+name: numbers
+input:
+- shape: "Circle"
+  formula: "A = pi * r^2"
+- shape: "Ellipse"
+  formula: "A = a * b * pi"
+- shape: "Trapezoid"
+  formula: "A = (a + b) * h / 2"
+- shape: "Pentagon"
+  formula: "A = a^2 * sqrt{25 + 10sqrt{5}} / 4"
+- shape: "Hexagon"
+  formula: "A = 3/2 * sqrt{3} * a^2"
+- shape: "Octagon"
+  formula: "A = 2 * (1 + sqrt{2}) * a^2"
\ No newline at end of file
diff --git a/02-primitives/01-numbers/exercise_test.go b/02-primitives/01-numbers/exercise_test.go
new file mode 100644
index 0000000..4cf09ae
--- /dev/null
+++ b/02-primitives/01-numbers/exercise_test.go
@@ -0,0 +1 @@
+// PLEASE RUN make generate
diff --git a/02-primitives/02-strings/.README.md b/02-primitives/02-strings/.README.md
new file mode 100644
index 0000000..c383fc5
--- /dev/null
+++ b/02-primitives/02-strings/.README.md
@@ -0,0 +1,7 @@
+# Strings - Change the network mask in the given CIDR address
+
+Write a small function, and change the network mask of the {{index . "cidr"}} CIDR address to {{index . "subnet"}} in the file `exercise.go` near the placeholder `// INSERT YOUR CODE HERE`. Do not use additional variables, or modify the existing code.
+
+Hint: Use strings.Split to split strings on an arbitrary delimiter.
+
+CIDR notation is a compact representation of an IP address and its associated network mask. The notation was invented by Phil Karn in the 1980s. CIDR notation specifies an IP address, a slash ('/') character, and a decimal number. The decimal number is the count of consecutive leading 1-bits (from left to right) in the network mask.
\ No newline at end of file
diff --git a/02-primitives/02-strings/.exercise_test.go b/02-primitives/02-strings/.exercise_test.go
new file mode 100644
index 0000000..6c5bd45
--- /dev/null
+++ b/02-primitives/02-strings/.exercise_test.go
@@ -0,0 +1,11 @@
+package strings
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReplaceNetMask(t *testing.T) {
+	assert.Equal(t, replaceNetMask("{{index . "cidr"}}", "{{index . "subnet"}}"), "{{index . "address"}}/{{index . "subnet"}}")
+}
diff --git a/02-primitives/02-strings/README.md b/02-primitives/02-strings/README.md
new file mode 100644
index 0000000..90c149f
--- /dev/null
+++ b/02-primitives/02-strings/README.md
@@ -0,0 +1 @@
+# PLEASE RUN make generate
diff --git a/02-primitives/02-strings/exercise.go b/02-primitives/02-strings/exercise.go
new file mode 100644
index 0000000..d63c449
--- /dev/null
+++ b/02-primitives/02-strings/exercise.go
@@ -0,0 +1,9 @@
+package strings
+
+//go:generate go run ../../exercises-cli.go -student-id=$STUDENT_ID generate
+
+// replaceNetMask will replace the subnet part of a CIDR address
+// Example -> 10.0.0.1/10 -> 10.0.0.1/14
+func replaceNetMask(address, newSubnet string) string {
+	// INSERT YOUR CODE HERE
+}
diff --git a/02-primitives/02-strings/exercise.yaml b/02-primitives/02-strings/exercise.yaml
new file mode 100644
index 0000000..19c9d0b
--- /dev/null
+++ b/02-primitives/02-strings/exercise.yaml
@@ -0,0 +1,20 @@
+name: "strings"
+input:
+- cidr: "192.168.1.1/24"
+  address: "192.168.1.1"
+  subnet: "26"
+- cidr: "10.0.0.138/12"
+  address: "10.0.0.138"
+  subnet: "24"
+- cidr: "10.0.1.1/16"
+  address: "10.0.1.1"
+  subnet: "24"
+- cidr: "192.168.254.254/24"
+  address: "192.168.254.254"
+  subnet: "32"
+- cidr: "127.0.0.0/1"
+  address: "127.0.0.0"
+  subnet: "16"
+- cidr: "152.66.115.203/32"
+  address: "152.66.115.203"
+  subnet: "32"
\ No newline at end of file
diff --git a/02-primitives/02-strings/exercise_test.go b/02-primitives/02-strings/exercise_test.go
new file mode 100644
index 0000000..4cf09ae
--- /dev/null
+++ b/02-primitives/02-strings/exercise_test.go
@@ -0,0 +1 @@
+// PLEASE RUN make generate
diff --git a/Makefile b/Makefile
index b608fe8..0c63933 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,8 @@
 # exercise subdirs
 EXERCISE_DIRS=\
 	01-getting-started \
+	02-primitives \
+	03-variables \
 	07-switch \
 	19-structs \
 	22-goroutines