Question 1 How many significant figures are in 43,000 ?

Step 1 ：The significant figures of a number are digits that carry meaning contributing to its measurement resolution. This includes all nonzero digits, zeroes between nonzero digits, and zeroes at the end of the number and to the right of the decimal. However, zeroes at the end of the number but to the left of an understood decimal point are not necessarily significant.

Step 2 ：In the number 43,000, the zeroes are to the left of an understood decimal point and it is not clear whether they are significant or not.

Step 3 ：Therefore, we can only confidently say that there are two significant figures (4 and 3).

Step 4 ：Final Answer: The number 43,000 has \(\boxed{2}\) significant figures.