Wednesday Wordplay is bustin' out all over here at the mentalfloss.com Brain Game.  Starting with the given I, add the letter provided in the next line and rearrange the existing letters (if necessary) to form a new English word. Add those to the letter in the next line (and rearrange) to form a new word, and so on, continuing all the way to EARTHLINGS. Good luck!

I
+T = _ _
+N = _ _ _
+L = _ _ _ _
+E = _ _ _ _ _
+S = _ _ _ _ _ _
+G = _ _ _ _ _ _ _
+R = _ _ _ _ _ _ _ _
+A = _ _ _ _ _ _ _ _ _
+H = E A R T H L I N G S

Here is one SOLUTION.

ONE SOLUTION:

NOTE: This is NOT the ONLY solution to this puzzle (the word ENLIST, for instance, could be rendered as TINSEL). Feel free to share in the comments if you came up with a different set of words that follows the pattern.

I
I+T = IT
IT + N = TIN
TIN + L = LINT
LINT + E = INLET
INLET + S = ENLIST
ENLIST + G = GLISTEN
GLISTEN + R = STERLING
STERLING + A = TRIANGLES
TRIANGLES + H = EARTHLINGS.