"Last night we did the array in the same way he did," Kong slowly said while closely inspecting something, "but we jumped over a little matter and didn't notice it before."
"Which is?" Kong said many things but failed to give any answer to what the headmaster asked about.
"He didn't use all the materials he got from you yesterday," Kong was now confident about this point before adding, "he is just using ten percent of the entire amount!"
"Only ten percent?!! How come?!" the headmaster finally realised what Kong meant.
The two paid close attention to every move William did, but missed such trivial detail about the amount of the materials he used.
They thought he placed the entire amount he received and didn't focus on how much he used. In return they just focused over what steps William took to form such an array.