When a quantity increases by the same factor over equal intervals of time, it is said that such a quantity is in exponential growth. Exponential growth is modeled using exponential functions where $a>0$ and $b>1.$ In this form, $a$ is the initial amount, the base $b$ is the growth factor, and $t$ usually represents time. Like any other exponential function, $a$ also represents the $y\text{-}$intercept. As shown, the greater the base $b,$ the faster the exponential function grows. Since the base $b$ is greater than $1,$ it can be written as the sum of $1$ and some positive number $r.$ This constant $r$ can then be interpreted as the rate of growth, in decimal form. For example, $r=0.06$ means that the quantity increases by $6\%$ over every unit of time.