Prof. Dumbledore is concerned that Harry, Ron and a few other students are still having some difficulties with significant figures. Hermione seems to have gotten it though. Why don’t we try to review them. How many significant figures does the result of the following expression have? (6.635-1.321)*(1747.4)*(3.54-2.6).

Answer: The expression has 6 significant figures.Step-by-step explanation:First =, we need to understand what significant figure is.Here's the definition: each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first non-zero digit. For example: 3.56 has 3 significant numbers23.51 has 4 significant figures3.450 has 4 significant figures, because even if the 0 after the 5 is there, we can remove it and the number remains the same.4.09 has 3 significant figures, because the 0 after the comma makes a difference.To know how many significant figures the expression has we need to solve it first, so:(6.635-1.321)*(1747.4)*(3.54-2.6) =5.314*1747.4*0.94 = 8728.548728.54 has 6 significant figures.