Open Middle®
Directions: Using the integers -9 to 9 at most one time each, place an integer in each box to create an equation where each side has the greatest possible value.
Hint
How can you verify the value of each side?
Answer
The greatest possible value is 16 and can be gotten through an equation like –-8 + 8 = 9 – (-7)
Source: Robert Kaplinsky
The greatest possible value I believe is 17. Since I can do
-(-9) + 8 = 9 – (-8), or -(-8) + 9 = 8 – (-9).
I used -9, 8, 9 , and -8 once each.