add some float operations with filesize (#6618)

* add some float operations with filesize

* more changes

* update return values on filesize-filesize, duration-duration

* missed filesize in floordiv

* missed float * duration

crates/nu-command/tests/commands/math/mod.rs

@@ -282,6 +282,66 @@ fn modulo() {
     assert_eq!(actual.out, "1");
 }
 
+#[test]
+fn unit_multiplication_math() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            1mb * 2
+        "#
+    ));
+
+    assert_eq!(actual.out, "1.9 MiB");
+}
+
+#[test]
+fn unit_multiplication_float_math() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            1mb * 1.2
+        "#
+    ));
+
+    assert_eq!(actual.out, "1.1 MiB");
+}
+
+#[test]
+fn unit_float_floor_division_math() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            1mb // 3.0
+        "#
+    ));
+
+    assert_eq!(actual.out, "325.5 KiB");
+}
+
+#[test]
+fn unit_division_math() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            1mb / 4
+        "#
+    ));
+
+    assert_eq!(actual.out, "244.1 KiB");
+}
+
+#[test]
+fn unit_float_division_math() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            1mb / 3.1
+        "#
+    ));
+
+    assert_eq!(actual.out, "315.0 KiB");
+}
+
 #[test]
 fn duration_math() {
     let actual = nu!(