\   ↓       ↓       ↓  /
   +---+---+---+---+---+  
  →| 4 | x |   | + |   | =?
   +---+---+---+---+---+  
   | x | x | + | x | x |
   +---+---+---+---+---+               
  →|   | - |   | x | 3 | =?
   +---+---+---+---+---+  
   | + | + | x | + | - |
   +---+---+---+---+---+    
  →|   | x | 5 | x |   | =?
   +---+---+---+---+---+ 
=?  =        =       =   =?
    ?        ?       ? 

Place the integers from 1 to 9 inclusive into the gaps in the above diagram. (The numbers 3, 4 and 5 have already been placed.)

When all the numbers are correctly placed in appropriate positions, there should be eight calculations the solutions to which should contain the same digits as the integers from 0 to 12 inclusively. (For example: 30, 12 and 45 has the same digits as integers from 0 to 5 inclusively, albeit these constitute part of the actual solution.)

1. The eight solutions should contain a two digit positive integer between 10 and 90 inclusively in place of each question mark.
2. There are three vertical, three horizontal and two diagonal calculations, the start of which is indicated by the appropriate arrow.
3. The symbols used are: addition (+), subtraction (-) and multiplication (x).

Order of operations: Multiplication(x), then addition(+) and then subtraction(-).