Fill in each of the boxes with the numbers 1 to 9 so that the three horizontal equations are true.

Each number is used once; no repetition is allowed.

The calculations are done from left to right (i.e., 7-2x3=15, not 1) and may involve only positive numbers (so 5-3-7=-5 is not allowed).

                               _     _     _     _
 _     _     _     _     _    | | - | | x | | = | |
| | x | | x | | = | | + | | + |_| + |_| + | | + |_|
|_| - |_| x |_| = |_| - |_|             - |_|

(In reply to re: allternate solution by Charlie)

I'm not sure I agree with Charlie on this point.  I think what has to be positive is the individual numbers inside each box, not necessarily the value of the equation.

" (so 5-3-7=-5 is not allowed)"  in this example "-5" would be the content of a box, and I suspect this is what is being disallowed.

But in "4 - 8 * 1 = 5 - 6 - 3"  all the boxes are filled with positive numbers.  It's true the evaluation of the equation leads to a negative number.

We'll have to ask Lisa which way fits what she was thinking.

Posted by Larry on 2005-10-06 20:28:23