Early research carried out in the 1800s, without the benefit of
computers, showed there is only one way to plug the numbers 1 to 9
(no zero) into this expression to make it valid in the mathematical
sense. All three parts of the expression are equal, as you can
see.
AB x C = DE - FG = HI
Finding the correct layout is no easy matter, however. To make
the problem more approachable, I have identified the odd/even state
of the nine integers as follows:
OO x E = OO - EO = EE
Find the solution online >>
