Crown without gem is 6 (because the red gem is 2, and the crown with the red gem is 8), ring without gem is 4 (since the blue gem is 3, and the ring with the blue gem is 7). So at the end, the blue and red gem equals 5, which you have to multiply with the ring with the red gem which equals 6, which means that part ends up 30. Then you add the crown with the blue gem, which equals 9, which altogether adds up to 39 (basically 9 + 5 x 6 = 39). Hope this helps!