The sum of 15 and 107 is 122.
122
122
The idea is to first add 122 + 230 (that's what "the sum of" means). Then, add 5 to the result.
2*(812+122) = 18682*(812+122) = 1868
122
78+79+80=237
It is: 48+74 = 122
45 + 46 + 47 + 48 + 122 = 308
58
122
The number sentence for the sum of 237, 459, and 92 is: 237 + 459 + 92 = 788. In this equation, the plus sign represents addition, and the numbers on either side of the plus sign are being added together to find the total sum.