The number 4.500060 has 7 significant digits.
Significant digits are the digits that carry meaningful information in a number. To determine the number of significant digits in a given number, we follow these rules:
1. Non-zero digits are always significant. In this case, the digits 4, 5, and 6 are non-zero and are therefore significant.
2. Zeros between non-zero digits are significant. In this case, the zero between the 5 and 6 is significant.
3. Leading zeros (zeros to the left of all non-zero digits) are not significant. In this case, the zero before the 4 is not significant.
4. Trailing zeros (zeros to the right of all non-zero digits) are significant only if there is a decimal point. In this case, the zeros after the 6 are significant because there is a decimal point after them.
Let's apply these rules to the number 4.500060:
1. The digits 4, 5, and 6 are non-zero and significant.
2. The zero between the 5 and 6 is significant.
3. The leading zero before the 4 is not significant.
4. The zeros after the 6 are significant because there is a decimal point after them.
Adding up the significant digits, we have a total of 7: 4, 5, 0, 0, 0, 6, and 0.
Therefore, the number 4.500060 has 7 significant digits.