So, I guessing the question is written wrong. The only thing that would make sense is "A carpenter took the following measurements: 3.4m, 10.25m, 20.2m, and 19m. How many SIGNIFICANT FIGURES does the sum of the measurements have?"
1. Add The Measurements
[tex]3.4m + 10.25m + 20.2m + 19.0m \\ = 52.85m[/tex]
52.85 Has 4 Significant Figures, this is the more precise measurement
HOWEVER, the rules of Significant Figures states that when adding we must put our answer in the same amount of decimal places as the least one in our expression. So 3.4has 1 decimal place, 10.25 has 2, 20.2 has 2, and 19.0 has 1. So we must put our answer only to the tens place and not the hundredth as we have it. OUR SIG FIG ANSWER IS;
[tex]52.9m[/tex]
This is considered less precise, for example 19 is just saying approximately 19, while 19.0 says this is exactly 19
