Hello! So if your project is turned in late, you get 8/9 of the points you would've received. In this case, you only received 72 points. To find out how many points you lost, first, let's find the score you could've gotten if it was turned in on time. Let's set up a proportion like this: 72/x = 8/9. Cross multiply the values to get 648 = 8x. Divide by 8 to isolate the "x" and you get x = 81. You could've originally gotten an 81. However, you only got a 72. To find out the amount of points you lost, subtract 72 from 81. 81 - 72 = 9. You lost 9 points from your original grade.