Add the series of aligned numbers and report the exact sum: 66066 + 6606 + 66 + 6 = ?

Introduction / Context:
This is an addition exercise with conveniently patterned numbers. Accuracy in column addition is essential. Recognizing the structure (each term is a sequence of sixes with different place values) can speed up mental computation while keeping errors at bay.

Given Data / Assumptions:

• Numbers: 66066, 6606, 66, 6
• We need the exact arithmetic sum.
• No rounding or estimation is required.

Concept / Approach:
Add the largest two numbers first, then successively add the smaller terms. Keeping a running total helps prevent misalignment of place values. Alternatively, note that 66066 + 6606 groups naturally because of similar digit patterns, making the first subtotal easy to verify.

Step-by-Step Solution:
1) 66066 + 6606 = 72672.2) 72672 + 66 = 72738.3) 72738 + 6 = 72744.4) Therefore, the final sum is 72744.

Verification / Alternative check:
Reverse-check by subtracting the smaller addends from the final sum: 72744 − 6 − 66 − 6606 = 66066, confirming the computation.

Why Other Options Are Wrong:
72798: Off by 54, likely from mishandling the step with 66.258126: Orders of magnitude too large; not consistent with the addends.None of these: Not applicable since 72744 is exact.

Common Pitfalls:
Misaligning place values when adding 6606 to 66066; dropping the carry when adding 66; or skipping the last +6 term. Writing each subtotal prevents these errors.

Final Answer:
72744