cannot determine value type from string 12kg

"12kg" is a string representing a value of weight. To convert it to a numerical value, you need to remove the "kg" part and convert the remaining string to a number. For example, in Python, you can do this:

weight_str = "12kg"
weight_num = float(weight_str.replace("kg", ""))
print(weight_num)  # Output: 12.0

This code replaces the "kg" part with an empty string, and then converts the resulting string to a float. The output is the numerical value of the weight, which is 12.0 in this case.