Answer: 501.0g
Explanation:
1) See the image attached.
2) The scale has three scales
3) The upper scale measures the ten units: it is at zero
4) The middle scale measures the hundreeds: it is at 500
5) the lower scale measures the units with 0.1 precision: it is at 1.0
Therefore the answer is 0 + 500 + 1.0 = 501.0