diff --git a/test/validation/test.bats b/test/validation/test.bats
new file mode 100644
index 0000000..686065e
--- /dev/null
+++ b/test/validation/test.bats
@@ -0,0 +1,59 @@
+#!/usr/bin/env bats
+
+bin() { ./scl.out $1 | tail -n1; }
+
+@test "simple addition" {
+    run bin "1+1"
+    [ "$output" = "= 2.000000" ]
+
+    run bin "-1+1"
+    [ "$output" = "= 0.000000" ]
+
+    run bin "1+-1"
+    [ "$output" = "= 0.000000" ]
+
+    run bin "-1+-1"
+    [ "$output" = "= -2.000000" ]
+}
+
+@test "simple subtraction" {
+    run bin "1-1"
+    [ "$output" = "= 0.000000" ]
+
+    run bin "-1-1"
+    [ "$output" = "= -2.000000" ]
+
+    run bin "1--1"
+    [ "$output" = "= 2.000000" ]
+
+    run bin "-1--1"
+    [ "$output" = "= 0.000000" ]
+}
+
+@test "simple multiplication" {
+    run bin "1*2"
+    [ "$output" = "= 2.000000" ]
+
+    run bin "-1*2"
+    [ "$output" = "= -2.000000" ]
+
+    run bin "1*-1"
+    [ "$output" = "= -1.000000" ]
+
+    run bin "-1*-1"
+    [ "$output" = "= 1.000000" ]
+}
+
+@test "simple division" {
+    run bin "1/2"
+    [ "$output" = "= 0.500000" ]
+
+    run bin "-1/2"
+    [ "$output" = "= -0.500000" ]
+
+    run bin "1/-1"
+    [ "$output" = "= -1.000000" ]
+
+    run bin "-1/-1"
+    [ "$output" = "= 1.000000" ]
+}