Tyler needs to get the windows in his new home cleaned. The cleaning company needs to know the total number of window panes before it can tell him how much the job will cost. There are 12 windows, each with four window panes across and four window panes down. Tyler can find the total number of window panes by multiplying the number of windows by the number of panes in each window. The total number of window panes is an expression with a whole-number exponent. Write an expression with exponents to find the total number of panes in 12 windows.