diff --git a/crates/genie-core/src/tools/number_words.rs b/crates/genie-core/src/tools/number_words.rs
index 8754c6a1..dc00911e 100644
--- a/crates/genie-core/src/tools/number_words.rs
+++ b/crates/genie-core/src/tools/number_words.rs
@@ -7,15 +7,25 @@ enum CardinalWord {
 }
 
 pub(crate) fn parse_spoken_number(tokens: &[&str], start: usize) -> Option<(u64, usize)> {
-    if let Some(Ok(value)) = tokens.get(start).map(|token| token.parse::<u64>()) {
-        return Some((value, start + 1));
-    }
-
     let mut total: u64 = 0;
     let mut group: u64 = 0;
     let mut index = start;
     let mut matched = false;
 
+    // A digit token ("5") immediately followed by a spelled magnitude
+    // ("hundred"/"thousand") must scale by it: "5 hundred" == 500, "3 thousand"
+    // == 3000. The old fast path returned the bare digit and silently dropped
+    // the magnitude ("5 hundred" -> 5). A digit with no trailing magnitude still
+    // returns immediately, exactly as before.
+    if let Some(Ok(value)) = tokens.get(start).map(|token| token.parse::<u64>()) {
+        if !matches!(tokens.get(start + 1).copied(), Some("hundred" | "thousand")) {
+            return Some((value, start + 1));
+        }
+        group = value;
+        index = start + 1;
+        matched = true;
+    }
+
     while let Some(&token) = tokens.get(index) {
         if matched
             && token == "and"
@@ -107,3 +117,36 @@ fn cardinal_word(token: &str) -> Option<CardinalWord> {
         _ => return None,
     })
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn digit_before_spelled_magnitude_scales() {
+        // "5 hundred" is 500; the old digit fast path returned 5 and silently
+        // dropped the magnitude word, so calculator/duration paths were wrong.
+        assert_eq!(parse_spoken_number(&["5", "hundred"], 0), Some((500, 2)));
+        assert_eq!(parse_spoken_number(&["3", "thousand"], 0), Some((3000, 2)));
+    }
+
+    #[test]
+    fn digit_magnitude_continues_like_spelled_numbers() {
+        let tokens = ["2", "thousand", "five", "hundred"];
+        assert_eq!(parse_spoken_number(&tokens, 0), Some((2500, 4)));
+        let tokens = ["5", "hundred", "and", "twenty"];
+        assert_eq!(parse_spoken_number(&tokens, 0), Some((520, 4)));
+    }
+
+    #[test]
+    fn bare_digit_without_magnitude_is_unchanged() {
+        assert_eq!(parse_spoken_number(&["5", "minutes"], 0), Some((5, 1)));
+        assert_eq!(parse_spoken_number(&["42"], 0), Some((42, 1)));
+    }
+
+    #[test]
+    fn spelled_magnitudes_still_parse() {
+        assert_eq!(parse_spoken_number(&["five", "hundred"], 0), Some((500, 2)));
+        assert_eq!(parse_spoken_number(&["hundred"], 0), Some((100, 1)));
+    }
+}