Perform the arithmetic operations.

Решение:

1. \( 684 + 121 = 805 \)
2. \( 920 + 39 = 959 \)
3. \( 136 - 124 = 12 \)
4. \( 296 - 269 = 27 \)
5. \( 254 + 453 = 707 \)
6. \( 654 + 185 = 839 \)

Ответ: 805, 959, 12, 27, 707, 839.