1. The problem is to add 126 and 7 by first rounding up and then subtracting. 2. First, round 126 up to the nearest ten. Since 126 is between 120 and 130, rounding up gives 130. 3. Next, add 7 to the rounded number: $$130 + 7 = 137$$. 4. Now subtract the difference between the rounded number and the original number. The difference is $$130 - 126 = 4$$. 5. Subtract this difference from the sum: $$137 - 4 = 133$$. 6. Therefore, the result of adding 126 and 7 by rounding up and then subtracting is 133.