First, you do the first exponent in the first part which is 10^3 and the answer for that is 1000. Then you do 2.4x1000 which is 2400. Afterwards you do the second part's exponent which is 10^2 and you get 100 for that. Next, you do 5.7x100 which is 570. Finally you add 2400+570 and get 2970.
