Go to the bank and get four $100 bills. Using a xacto knife, cut out all of the serial numbers of the bills. Then, cut off 1/4 of each bill in the follow method:

  * Cut 1/4 off the left hand side of the first bill.
  * Cut a rectangle out of the next bill using these coordinates:  Top: 1px, Height: 100%-2px, Left: 25%, Width: 25% ... where 1px is about 1/8 inch.
  * Cut a rectangle out of the third bill using these coordinates:  Top: 1px, Height: 100%-2px, Left: 50%, Width: 25%

You now have:

  * One bill with the left quadrant cut off.
  * One bill with a big rectangle cut out... but is still barely in tact.
  * Another bill with a big rectangle cut out.
  * Three 1/4 pieces that you tape together to create a 4th mutilated $100 bill.

Go to the bank, and retrieve your hard earned $400.

Source: http://wiki.answers.com/Q/Will_a_bank_replace_a_half_ten_dol...