There are only two possibilities for the multiplication
We cannot use a 1 since that would make the product be the
same as the other number. Those two possibilities
for the multiplication are:
2×3 = 6 and 2×4 = 8
Let's try 2×4 = 8
That leaves 1,3,5,6,7,9
The addition could be 1+5=6 leaving 3,5, and 7.
But no subtraction can be made from those.
The addition could be 1+6=7 leaving 3,5, and 9.
But no subtraction can be made from those.
The addition could be 3+6=9 leaving 1,5, and 7.
But no subtraction can be made from those.
So we have ruled out 2×4=8 for the multiplication
So the multiplication can only be 2×3 = 6
That leaves 1,4,5,7,8,9
The addition could be 1+4=5 leaving 7, 8, and 9.
But no subtraction can be made from those.
The addition could be 1+8=9 leaving 4, 5, and 7.
But no subtraction can be made from those.
The addition could be 1+7=8 leaving 4,5, and 9.
And the subtraction could be 9-5=4 or 9-4=5
So here are two possibilities so far:
9-5=4 9-4=5
1+7=8 and 1+7=8
2×3=6 2×3=6
The addition could be 4+5=9 leaving 1,7, and 8.
And the subtraction could be 8-1=7. So that's another
possibility:
8-1=7
4+5=9
2×3=6
Edwin
