In the simulation pane select the option for 'Select Chips and Press the D Key'. Click on one of the leftover material pieces and hit 'D' on the keyboard.
Alternatively, hold down the 'Ctrl' key and pick the stock piece to keep, then press the D key to remove the loose chips. Click the Remove Chips button to exit the chip removal function.
Updated 11/21/2016 by Esther Park