You are going to first multiply 5x7 together to get 35 then you are going to add a zero before multiplying 1x7 which equals 7 then you are going to add another zero and multiply 5x2 to get 10 and lastly you are going to add 2 zeros and multiply 2x1 and you will get 2. Lastly you are going to add all the values to get 405.
