There are 3 meatballs on each spaghetti plate.  If Theresa's 3 sons each eat two-thirds of the meatballs on their respective plates, how many meatballs are still left on their plates altogether?
Total meatballs on the plates 3 x 3 = <<3*3=9>>9.
If two-thirds are eaten, one-third remaining on the plates is 9 / 3 = <<9/3=3>>3.
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