I got 9. The 3 div 1/3 gave me pause since I haven’t dealt with fractions in forever. With the boxes example, 3 boxes divided into 3 would mean 3 little things. Each little thing is a single whole, or 1.
Operator precedence goes left to right with division/Mult first so that must be done first.
So 9 - 1 + 1 = 9
Fun little challenge!