Round-up is optional for all cardholders. Those who which to participate should set a threshold from $1 to $500 to activate round-up. The round-up works very simply - it rounds up the purchase amount to the nearest dollar. Let's say you make a purchase in the amount of $5.15, your round up amount will be $0.85 because the next whole dollar amount is $6.00. Round-up amounts earn 1,25% cashback, too.