diff --git a/README.md b/README.md
index 8032be5..acbf9c2 100644
--- a/README.md
+++ b/README.md
@@ -894,21 +894,24 @@ var=$((var2 > var ? var2 : var))
 is_float() {
     # Usage: is_float "number"
 
-    # The test checks to see that the input contains
-    # a '.'. This filters out whole numbers.
-    [ -z "${1##*.*}" ] &&
-        printf %f "$1" >/dev/null 2>&1
+    # Printing as '%d' must fail in order to filter out whole numbers;
+    # then printing as '%f' will succeed if and only if '$1' is a float.
+    # This works for both decimal point form (i.g. 3.14) and standard form
+    # (e.g. 314e-2).
+    { ! printf %d "$1" && printf %f "$1" ; } >/dev/null 2>&1
 }
 ```
 
 **Example Usage:**
 
 ```shell
-$ is_float 1 && echo true
-$
+$ is_float 3 && echo true
 
-$ is_float 1.1 && echo true
-$ true
+$ is_float 3.14 && echo true
+true
+
+$ is_float 314e-2 && echo true
+true
 ```
 
 ## Check if a number is an integer
@@ -926,10 +929,9 @@ is_int() {
 
 ```shell
 $ is_int 1 && echo true
-$ true
+true
 
 $ is_int 1.1 && echo true
-$
 ```
 
 # TRAPS