If you 
deposit $35, you can imagine drawing a green line (representing the money gained) to the 35 on the number line, which can be seen as 
moving 35 to the right
. Fo 
withdrawing, imagine drawing a red line back 50 notches on the number line (representing money lost). The net effect that the deposit and withdrawal will have on your account balance is a 

 dollar 
loss, which can be represented on the number line as a line drawn to the point -15.