Answer: The USD total of a pool is calculated by taking the total number of LP tokens and dividing it by the Total Value Locked (TVL) in the pool. This gives the USD value of each LP token, which is then multiplied by the total number of LP tokens to get the total USD value of the pool. The TVL is the total amount of funds locked in the pool, which is determined by the amount of liquidity providers who have deposited their tokens into the pool. By dividing the total number of LP tokens into the TVL, it is possible to calculate the USD total of the pool.