diff --git a/src/nodes/from_str.rs b/src/nodes/from_str.rs
index 95f25a7..f6dfbd6 100644
--- a/src/nodes/from_str.rs
+++ b/src/nodes/from_str.rs
@@ -29,6 +29,10 @@ impl FromStr for Nodes {
         let mut state = ParsingState::default();
 
         let is_ignored_char = |c: &char| !matches!(c, ' ' | '&' | '\n');
+        let is_numeric_char = |c: char| match c {
+            '.' | 'e' => true,
+            c => c.is_numeric(),
+        };
 
         let filtered_string: String = s.chars().filter(is_ignored_char).collect();
 
@@ -49,7 +53,7 @@ impl FromStr for Nodes {
                     }
                 }
                 ParsingState::ReadingNumber(start_index) => {
-                    if !c.is_numeric() {
+                    if !is_numeric_char(c) {
                         nodes.push(Node::Number(
                             Float::parse_radix(&filtered_string[start_index..i], 10)
                                 .map_err(|e| {
@@ -68,10 +72,10 @@ impl FromStr for Nodes {
             }
 
             if start {
-                if c.is_alphabetic() {
-                    state = ParsingState::ReadingFunctionName(i);
-                } else if c.is_numeric() {
+                if is_numeric_char(c) {
                     state = ParsingState::ReadingNumber(i);
+                } else if c.is_alphabetic() {
+                    state = ParsingState::ReadingFunctionName(i);
                 } else if c == '(' {
                     nodes.push(Node::ParenthesisStart);
                 } else if c == ')' {