diff --git a/logic-exercises/01fev.js b/logic-exercises/01fev.js
new file mode 100644
index 0000000..75391d1
--- /dev/null
+++ b/logic-exercises/01fev.js
@@ -0,0 +1,25 @@
+let arr1to100= [] ;
+
+for (let i = 1; i < 101; i++) {
+    arr1to100.push(i)
+  };
+
+console.log("length 100: ", arr1to100.length);
+
+const outNumber = Math.floor(Math.random() * 10) + 1;
+
+arr1to100.splice(outNumber, 1);
+
+console.log("length 99: ", arr1to100.length);
+
+let count = 0;
+
+for (let value of arr1to100) {
+  count += value
+}
+
+const diff = ( 5050 - count )
+
+console.log("Missing number is: ", diff)
+
+//console.log(arr1to100[0],arr1to100[1],arr1to100[98], arr1to100[99])
\ No newline at end of file