You got it almost right.
Clocks values are the hours: 9 + 9 +3 = 21
Calculators are the sum of the numbers displayed: (1+2+3+4) + (1+2+3+4) + (1+2+3+4) = 30
Bulbs are based on the rays of light above the bulb : (5x) + (5x) - (5x) = 15; x=3
Here's the start of the calculation: (9) + ((1+2+2+4) x (4x3)) = 117
The difference was that on the last picture there are three bulbs with 4 rays each instead of 5.