The answer to the correct number of significant figures is 42.21
When adding decimal numbers, the number of significance of the resulting value will be to the least decimal numbers in the given expression.
Given the sum of decimal shown
41.70 + 0.506 + 0.00223
Using the calculator to take the sum
41.70 + 0.506 + 0.00223 = 42.20823
Since the significance value in the expression is 4, hence we will round the result to 4sf to have 42.21
Learn more on addition of decimal here: https://brainly.com/question/19127052
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