Final answer:
The value of the computation 12.34 + 3456 - 0.056 based on significant figures is 3468.28.
Step-by-step explanation:
To calculate the value of the expression 12.34 + 3456 - 0.056 based on significant figures, we need to consider the number of significant figures in each term.
In 12.34, there are four significant figures. In 3456, there are four significant figures as well. And in 0.056, there are two significant figures.
Since addition and subtraction involve aligning the decimal places, we can keep the same number of decimal places. Thus, the answer will have the least number of decimal places, which is two in this case.
Adding 12.34 and 3456, we get 3468.34. Subtracting 0.056, we get 3468.284. Rounding to two decimal places, the final answer is 3468.28.