Bank tellers need strong math skills to count and handle large amounts of money. When a customer wants to withdraw money, tellers must determine whether the client's account balance meets the requirement for the transaction. When they buy and sell currency from bank vaults for cash drawers, tellers need the ability to stay within cash limits. Their cash drawers need daily balancing as well. These duties require the skill to add, subtract, multiply and divide quickly and correctly. Even an understanding of algebra, geometry, calculus and statistics comes in handy. Those disciplines shape the ability to use math to solve problems, and to understand basic accounting principles and practices.