Question

how many significant figures are in this mass? 6,906 mg

Explanation:

Step1: Recall significant figure rules

Significant figures: Non - zero digits are significant. Zeros between non - zero digits are significant.

Step2: Analyze the number 6,906

In the number 6,906, the digits are 6, 9, 0, 6. The non - zero digits 6, 9, 6 are significant, and the zero between 9 and 6 is also significant. So we count all the digits: 6 (first), 9, 0, 6 (fourth).

Answer:

4