Add Split A Float Into Its Integer And Decimal as a Ruby TIL

Author: jbranchaud

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1268 TILs and counting..._
+_1269 TILs and counting..._
 
 ---
 
@@ -1084,6 +1084,7 @@ _1268 TILs and counting..._
 - [Single And Double Quoted String Notation](ruby/single-and-double-quoted-string-notation.md)
 - [Skip Specific CVEs When Auditing Your Bundle](ruby/skip-specific-cves-when-auditing-your-bundle.md)
 - [Specify Dependencies For A Rake Task](ruby/specify-dependencies-for-a-rake-task.md)
+- [Split A Float Into Its Integer And Decimal](ruby/split-a-float-into-its-integer-and-decimal.md)
 - [Squeeze Out The Extra Space](ruby/squeeze-out-the-extra-space.md)
 - [String Interpolation With Instance Variables](ruby/string-interpolation-with-instance-variables.md)
 - [Summing Collections](ruby/summing-collections.md)

ruby/split-a-float-into-its-integer-and-decimal.md

@@ -0,0 +1,29 @@
+# Split A Float Into Its Integer And Decimal
+
+Let's say we have a float value like `3.725`. We want to break it up into its
+constituent parts -- the integer part (`3`) and the decimal part (`0.725`).
+
+This can be done with the `divmod` method on the `Numeric` class.
+
+```ruby
+3.725.divmod(1)
+=> [3, 0.7250000000000001]
+```
+
+In the general case, this method gives you the quotient and the modulus of
+dividing the number by the given value. When that given value is specifically
+`1`, it will give you those two parts of the float.
+
+One place where this might be useful is when trying to convert a float
+representing an amount of time into hours and minutes.
+
+```ruby
+hours = 3.725
+
+hours_digit, percentage_minutes = hours.divmod(1)
+
+minutes = (60 * percentage_minutes).to_i
+hours_standard = "#{hours_digit}:#{minutes}"
+```
+
+[source](https://ruby-doc.org/core-2.5.3/Numeric.html#method-i-divmod)