Theo needs $40,000 as a down payment for a house 6 years from now. He earns 3.5 percent on his savings.

Theo needs $40,000 as a down payment for a house 6 years from now. He earns 3.5 percent on his savings. Theo can either deposit one lump sum today for this purpose or he can wait a year and deposit a lump sum. How much additional money must he deposit if he waits for one year rather than making the deposit today?