It depends on what you consider to be "customary" and what you wish to convert them to.
If you don't know their equivalence, then you can either get a common denominator, and compare the numerators. Or you can divide and convert them all to decimal form and then compare.
You can convert units of length to units of length, and units of area to units of area. But it doesn't make sense to convert between units of length and units of area.
It doesn't make sense to convert that. You can convert units of length to units of length, for example; but you can't convert a pure number to a length.
It doesn't make sense to convert that. You can only convert units of the same kind, e.g., units of length to units of length; units of area to units of area; units of time to units of time, etc.
To convert a value from SI units to U.S. customary units, you need to identify the appropriate conversion factor for the specific measurement (e.g., length, weight, volume). Multiply the SI value by this conversion factor to obtain the equivalent value in U.S. customary units. Ensure that you maintain the correct units throughout the calculation for accuracy. You can find conversion factors in reference materials or online conversion tools.
You use conversion factors.
If you don't know their equivalence, then you can either get a common denominator, and compare the numerators. Or you can divide and convert them all to decimal form and then compare.
-- inch -- foot -- yard -- rod -- chain -- league -- furlong -- mile
metric
You can convert units of length to units of length, and units of area to units of area. But it doesn't make sense to convert between units of length and units of area.
It doesn't make sense to convert that. You can convert units of length to units of length, for example; but you can't convert a pure number to a length.
It doesn't make sense to convert that. You can only convert units of the same kind, e.g., units of length to units of length; units of area to units of area; units of time to units of time, etc.
10 1/2
To convert 17.42 meters to customary units (feet), you multiply by the conversion factor of approximately 3.28084 feet per meter. Thus, 17.42 meters is equivalent to about 57.188 feet. You can round this to 57.19 feet for simplicity.
There are different ways of converting weight, length, volume etc.
It doesn't make sense to convert units that measure completely different things. You can only convert units of length to units of length, units of mass to units of mass, etc.
You can't convert that. You can only convert units that measure the same type of thing - for example, units of length to units of length, units of mass to units of mass, units of time to units of time, etc.