x is the number you thinkc
that's it
x/2 -4
That would be the ones place, because 7 would be the tens place, 6 would be the hundreds place, and 5 would be the thousands place.
Hope this helped >.<
Answer:
How much per a pencil and eraser? I'll help you out from there :)
So 10 questions is 100% you missed 30% of the questions so you would do 100%-30% which is 70%