Solve the equation: \[\Box - 310 = 547 - 204\]

Let's solve the equation step by step: 1. First, simplify the right side of the equation: $$547 - 204 = 343$$ 2. Now the equation looks like this: $$\Box - 310 = 343$$ 3. To find the unknown number (represented by the box), add 310 to both sides of the equation: $$\Box = 343 + 310$$ 4. Calculate the sum: $$\Box = 653$$ So, the missing number is 653. Answer: 653