Prealgebra (7th Edition)

$4^3$
An exponent represents repeated multiplication. $\underset\uparrow e^{b\ \leftarrow\ number\ of\ times\ the\ base\ appears\ as\ a\ factor}$ the base is the factor that is multiplied $4\times4\times4=4^3$ 4 is the factor so is the base. The factor appears 3 times so the exponent is 3.