diff --git a/apps/gridcraft-cli/src/main.rs b/apps/gridcraft-cli/src/main.rs
index 972c023fa..5170ba0c5 100644
--- a/apps/gridcraft-cli/src/main.rs
+++ b/apps/gridcraft-cli/src/main.rs
@@ -195,7 +195,18 @@ fn pretty(v: &Value) -> String {
 
 /// A number as a person would type it: `6`, `0.5`, `1e+300`.
 fn number_text(n: f64) -> String {
-    if n.fract() == 0.0 && n.abs() < 1e15 { format!("{}", n as i64) } else { format!("{n}") }
+    if n.fract() == 0.0 && n.abs() < 1e15 {
+        format!("{}", n as i64)
+    } else if n.is_finite() && (n.abs() >= 1e15 || n.abs() < 1e-5) {
+        // Rust's `Display` never uses exponent form; `{:e}` omits the `+` on positive exponents.
+        let s = format!("{n:e}");
+        match s.split_once('e') {
+            Some((m, e)) if !e.starts_with('-') => format!("{m}e+{e}"),
+            _ => s,
+        }
+    } else {
+        format!("{n}")
+    }
 }
 
 /// A computed value (as returned by `formulas.evaluate` / `sheet.read`) as plain text.
@@ -606,6 +617,11 @@ mod tests {
     fn value_texts() {
         assert_eq!(value_text(&json!(6.0)), "6");
         assert_eq!(value_text(&json!(0.25)), "0.25");
+        assert_eq!(value_text(&json!(1e300)), "1e+300");
+        assert_eq!(value_text(&json!(-1.5e300)), "-1.5e+300");
+        assert_eq!(value_text(&json!(1e-20)), "1e-20");
+        assert_eq!(value_text(&json!(1e-300)), "1e-300");
+        assert_eq!(value_text(&json!(0.0001)), "0.0001");
         assert_eq!(value_text(&json!(true)), "TRUE");
         assert_eq!(value_text(&json!({"error": "#DIV/0!"})), "#DIV/0!");
         assert_eq!(value_text(&json!([[1.0, 2.0], [3.0, "x"]])), "1\t2\n3\tx");