diff --git a/src/formatting.rs b/src/formatting.rs
index a278c4b..bf321bc 100644
--- a/src/formatting.rs
+++ b/src/formatting.rs
@@ -87,33 +87,34 @@ pub fn get_significant_digits(n: &Float) -> usize {
 #[cfg(test)]
 mod tests {
     use super::*;
+    const MAX_DIGITS: usize = 10;
     fn eval(s: &str) -> Float {
         crate::nodes::eval(s).unwrap()
     }
 
     #[test]
     fn character_readdition() {
-        assert_eq!(pretty_eval(" = 11", 10).unwrap(), " = 11");
-        assert_eq!(pretty_eval(" &= 11", 10).unwrap(), " &= 11");
-        assert_eq!(pretty_eval(" & 11", 10).unwrap(), " & 11");
-        assert_eq!(pretty_eval(" & 11 \\", 10).unwrap(), " & 11 \\");
+        assert_eq!(pretty_eval(" = 11", MAX_DIGITS).unwrap(), " = 11");
+        assert_eq!(pretty_eval(" &= 11", MAX_DIGITS).unwrap(), " &= 11");
+        assert_eq!(pretty_eval(" & 11", MAX_DIGITS).unwrap(), " & 11");
+        assert_eq!(pretty_eval(" & 11 \\", MAX_DIGITS).unwrap(), " & 11 \\");
     }
 
     #[test]
     fn basic_output_up_to_999() {
-        assert_eq!(pretty_eval("1", 10).unwrap(), "1");
-        assert_eq!(pretty_eval("10", 10).unwrap(), "10");
-        assert_eq!(pretty_eval("100", 10).unwrap(), "100");
-        assert_eq!(pretty_eval("999", 10).unwrap(), "999");
-        assert_eq!(pretty_eval("1000", 10).unwrap(), "1 * 10^3");
+        assert_eq!(pretty_eval("1", MAX_DIGITS).unwrap(), "1");
+        assert_eq!(pretty_eval("10", MAX_DIGITS).unwrap(), "10");
+        assert_eq!(pretty_eval("100", MAX_DIGITS).unwrap(), "100");
+        assert_eq!(pretty_eval("999", MAX_DIGITS).unwrap(), "999");
+        assert_eq!(pretty_eval("1000", MAX_DIGITS).unwrap(), "1 * 10^3");
 
-        assert_eq!(pretty_eval("11.111111", 10).unwrap(), "11.111111");
+        assert_eq!(pretty_eval("11.111111", MAX_DIGITS).unwrap(), "11.111111");
     }
 
     #[test]
     fn plus_minus() {
         assert_eq!(
-            pretty_eval("y & = plus.minus sqrt(15.5) \\", 10).unwrap(),
+            pretty_eval("y & = plus.minus sqrt(15.5) \\", MAX_DIGITS).unwrap(),
             "y & = plus.minus 3.937003937 \\"
         );
     }