Friday Puzzle #117 - Only Five TomTom
Example (with 1-3):
Rules: Place a digit from 1 to 5 (or no digit at all) into each cell so that each digit appears exactly once in each row and column. The values in the upper-left of the bold cages indicate the value of an operation applied to all the digits entered into that cage. Numbers can repeat within a cage. Blank cells do not influence the values of the operations.