Justin has made 40% of the illustrations. First, calculate the number of illustrations Justin has made, by calculating the 40% of 80, just as follow:
(40/100)(80) = 32
that is, 40% is claculated by multiplying 40/100 by 80.
Then, justis has made 32 illustrations. To obtain the number of illustrations Justin has not made even, subtract the previous result to 80:
80 - 32 = 48
Then, Justin has not made 48 illustrations.
A bar model representing the previous situation is shown below:
where the red regios corresponds to the 32 illustrations made by Justin