3/5 of digit is something you do with a shovel.

Use only three of the five letters from the word "digit"; what does one generally do with a shovel?

diging?

Dig

To solve this riddle, you need to find a word that describes an activity involving a shovel and fits the criteria of being 3 out of 5 letters.

One way to approach this is to think of common words associated with shovels and then narrow them down based on their length. Some words that come to mind are dig, bury, scoop, and rake.

Using the given information, "3/5 of a digit," we can deduce that the word we are looking for has 3 letters. From the options we brainstormed, "dig" fits the criteria.

Therefore, the answer to the riddle is "DIG."