The first significant figure is the leading 2 but, to one sig fig, the number is 30000.
It is the first figure that's not a zero. This applies to all numbers.
The first significant figure of 0.000169 is the 1 and it has 3 significant figures.
0.019 to 1 significant figure is 0.02 (significant figure is counted from the left with 1st significant being the first non-zero from the left)
The number 327 to one significant figure is 300. The digit 3 is the first and only significant figure, and numbers after this digit are considered not significant.
849 to 1 significant figure is 800. This is because the first non-zero digit is 8, so the significant figure is the hundreds place.
The significant figure of a number refers to the non-zero digits and any zeros that are between them or at the end of the number. In the number 257166, the first significant figure is 2, as it is the first non-zero digit in the number.
2,000
4
It is then 30,000 rounded to 1 significant figure
The first significant figure is the first number which is not zero (in this case, it is the three). All numbers beyond this are significant. So the third significant figure is the 9. In this case, the number rounds down to 0.0309
When expressing a number to one significant figure, you round the number to the nearest power of 10. In this case, 9862 to one significant figure would be 10,000. This is because the first digit from the left is 9, which is closer to 10 than 10000.
37.753 rounded to one significant figure becomes 40