Over the years, many examples of transadditions have appeared in Word Ways. A transaddition is the result of adding a letter to a word and then rearranging all the letters to form another, longer word. It is relatively easy to start with a single letter and, step by step, achieve transadditions up to length 7 or 8 letters. Longer ones are more difficult.
Word Ways: Vol. 33
, Article 16.
Available at: http://digitalcommons.butler.edu/wordways/vol33/iss4/16